From 49f2850c5eeead43e65b31d68b694c2d3b81f684 Mon Sep 17 00:00:00 2001
From: DuHouAn <18351926682@163.com>
Date: 2019年7月25日 23:46:18 +0800
Subject: [PATCH 1/2] Java
---
 ...345円215円260円351円223円276円350円241円250円.java" &#124; 32 +++++++
 ...347円232円204円346円225円260円345円255円227円.java" &#124; 38 +++++++++
 ...345円276円205円345円244円204円347円220円206円.java" &#124; 37 +++++++++
 ...347円247円257円346円225円260円347円273円204円.java" &#124; 36 ++++++++
 ...347円232円204円350円267円257円345円276円204円.java" &#124; 83 +++++++++++++++++++
 5 files changed, 226 insertions(+)
 create mode 100644 "docs/AimForOffer/344円273円216円345円260円276円345円210円260円345円244円264円346円211円223円345円215円260円351円223円276円350円241円250円.java"
 create mode 100644 "docs/AimForOffer/346円225円260円347円273円204円344円270円255円351円207円215円345円244円215円347円232円204円346円225円260円345円255円227円.java"
 create mode 100644 "docs/AimForOffer/346円234円272円345円231円250円344円272円272円347円232円204円350円277円220円345円212円250円350円214円203円345円233円264円_345円276円205円345円244円204円347円220円206円.java"
 create mode 100644 "docs/AimForOffer/346円236円204円345円273円272円344円271円230円347円247円257円346円225円260円347円273円204円.java"
 create mode 100644 "docs/AimForOffer/347円237円251円351円230円265円344円270円255円347円232円204円350円267円257円345円276円204円.java"
diff --git "a/docs/AimForOffer/344円273円216円345円260円276円345円210円260円345円244円264円346円211円223円345円215円260円351円223円276円350円241円250円.java" "b/docs/AimForOffer/344円273円216円345円260円276円345円210円260円345円244円264円346円211円223円345円215円260円351円223円276円350円241円250円.java"
new file mode 100644
index 0000000..c73507b
--- /dev/null
+++ "b/docs/AimForOffer/344円273円216円345円260円276円345円210円260円345円244円264円346円211円223円345円215円260円351円223円276円350円241円250円.java"
@@ -0,0 +1,32 @@
+import java.util.ArrayList;
+
+/**
+ * Created by DHA on 2019年7月22日.
+ */
+public class 从尾到头打印链表 {
+ //从尾到头打印链表
+ public ArrayList<integer> printListFromTailToHead(ListNode listNode) {
+ ArrayList<integer> res = new ArrayList<strong>();
+
+ //逆置该链表
+ ListNode head = reverse(listNode);
+ while(head!=null){
+ res.add(head.val);
+ head = head.next;
+ }
+ return res;
+ }
+
+ private ListNode reverse(ListNode listNode){
+ ListNode pre = null;
+ ListNode cur = listNode;
+ while(cur!=null){
+ ListNode next = cur.next;
+ cur.next = pre;
+
+ pre = cur;
+ cur = next;
+ }
+ return pre;
+ }
+}
diff --git "a/docs/AimForOffer/346円225円260円347円273円204円344円270円255円351円207円215円345円244円215円347円232円204円346円225円260円345円255円227円.java" "b/docs/AimForOffer/346円225円260円347円273円204円344円270円255円351円207円215円345円244円215円347円232円204円346円225円260円345円255円227円.java"
new file mode 100644
index 0000000..3dd4684
--- /dev/null
+++ "b/docs/AimForOffer/346円225円260円347円273円204円344円270円255円351円207円215円345円244円215円347円232円204円346円225円260円345円255円227円.java"
@@ -0,0 +1,38 @@
+import org.junit.Test;
+
+/**
+ * Created by DHA on 2019年7月22日.
+ */
+public class 数组中重复的数字 {
+ //数组中重复的数字
+ public boolean duplicate(int numbers[],int length,int [] duplication) {
+ for(int i=0;i<length;i++){ + if(numbers[i]!=numbers[numbers[i]]){ + swap(numbers,i,numbers[i]); + i--; + } + } + + for(int i=0;i<length;i++){ + if(numbers[i]!=i){ + duplication[0]=numbers[i]; + return true; + } + } + return false; + } + + private void swap(int[] nums,int i,int j){ + int tmp = nums[i]; + nums[i] = nums[j]; + nums[j] = tmp; + } + + @Test + public void test(){ + int[] nums = {2,3,1,0,2,5,3}; + int[] duplication = new int[nums.length]; + System.out.println(duplicate(nums,nums.length,duplication)); + System.out.println(duplication[0]); + } +} diff --git "a/docs/AimForOffer/346円234円272円345円231円250円344円272円272円347円232円204円350円277円220円345円212円250円350円214円203円345円233円264円_345円276円205円345円244円204円347円220円206円.java" "b/docs/AimForOffer/346円234円272円345円231円250円344円272円272円347円232円204円350円277円220円345円212円250円350円214円203円345円233円264円_345円276円205円345円244円204円347円220円206円.java" new file mode 100644 index 0000000..ada8700 --- /dev/null +++ "b/docs/AimForOffer/346円234円272円345円231円250円344円272円272円347円232円204円350円277円220円345円212円250円350円214円203円345円233円264円_345円276円205円345円244円204円347円220円206円.java" @@ -0,0 +1,37 @@ +import org.junit.Test; + +/** + * Created by DHA on 2019/7/25. + */ +public class 机器人的运动范围 { + private int m,n; + + private int[][] d={ + {0,1}, //向右 + {-1,0},//向上 + {0,-1},//向左 + {1,0} //向下 + }; + + //获取一个数各个位上的数字相加 + private int getNum(int num){ + int sum = 0; + while(num>0){
+ sum += num %10;
+ num/=10;
+ }
+ return sum;
+ }
+
+
+
+ public int movingCount(int threshold, int rows, int cols) {
+
+ }
+
+ @Test
+ public void test(){
+ int num = 37;
+ System.out.println(getNum(num));
+ }
+}
diff --git "a/docs/AimForOffer/346円236円204円345円273円272円344円271円230円347円247円257円346円225円260円347円273円204円.java" "b/docs/AimForOffer/346円236円204円345円273円272円344円271円230円347円247円257円346円225円260円347円273円204円.java"
new file mode 100644
index 0000000..bb5acd5
--- /dev/null
+++ "b/docs/AimForOffer/346円236円204円345円273円272円344円271円230円347円247円257円346円225円260円347円273円204円.java"
@@ -0,0 +1,36 @@
+import org.junit.Test;
+
+/**
+ * Created by DHA on 2019年7月22日.
+ */
+public class 构建乘积数组 {
+ //构建乘积数组
+ //思路:
+ //B[i]=A[0]*A[1]*...*A[i-1]*A[i+1]*...*A[n-1]。
+ //B[i] 可拆分成 (A[0]*A[1]*...*A[i-1])*(A[i+1]*...*A[n-1])两部分
+ public int[] multiply(int[] A) {
+ int n = A.length;
+ int[] B = new int[n];
+
+ //B[i] = A[0]*A[1]*...*A[i-1]
+ int product =1;
+ for(int i=0;i<n;product*=a[i],i++){ + B[i] = product; + } + //B[i] = B[i] * (A[i+1]*...*A[n-1]) + product=1; + for(int i=n-1;i>=0;product*=A[i],i--){
+ B[i]*= product;
+ }
+ return B;
+ }
+
+ @Test
+ public void test(){
+ int[] A={1,2,3,4,5};
+ int[] B=multiply(A);
+ for(int num:B){
+ System.out.println(num);
+ }
+ }
+}
diff --git "a/docs/AimForOffer/347円237円251円351円230円265円344円270円255円347円232円204円350円267円257円345円276円204円.java" "b/docs/AimForOffer/347円237円251円351円230円265円344円270円255円347円232円204円350円267円257円345円276円204円.java"
new file mode 100644
index 0000000..37c982c
--- /dev/null
+++ "b/docs/AimForOffer/347円237円251円351円230円265円344円270円255円347円232円204円350円267円257円345円276円204円.java"
@@ -0,0 +1,83 @@
+import org.junit.Test;
+
+/**
+ * Created by DHA on 2019年7月25日.
+ */
+public class 矩阵中的路径 {
+ private int m,n; //矩阵的长度、宽度
+ private boolean[][] visted; //标记是否访问
+
+ private int[][] d={
+ {0,1}, //向右
+ {-1,0},//向上
+ {0,-1},//向左
+ {1,0} //向下
+ };
+
+ private boolean inArea(int x,int y){
+ return (x>=0 && x<m) && (y>=0 && y<n); + } + + //从board[startx][starty]开始寻找word[index...word.ength()] + private boolean searchMatrix(char[][] matrix, char[] str,int index,int startx,int starty){ + if(index==str.length-1){ //递归到最后一个元素,检测是否相等 + return matrix[startx][starty] == str[index]; + } + if(matrix[startx][starty]==str[index]){ + visted[startx][starty] = true; + for(int i=0;i<4;i++){ + int newX = startx+d[i][0]; + int newY = starty+d[i][1]; + if(inArea(newX,newY) && !visted[newX][newY]){ + if(searchMatrix(matrix,str,index+1,newX,newY)){ + return true; + } + } + } + visted[startx][starty] =false; + } + return false; + } + + //构建二维矩阵 + private char[][] buildMatrix(char[] array, int rows, int cols){ + //根据char[] matrix, rows, cols 构建二维的矩阵 + char[][] matrix = new char[rows][cols]; + int index=0; + for(int i=0;i<rows;i++) { + for (int j = 0; j < cols; j++) { + matrix[i][j] = array[index++]; + } + } + return matrix; + } + + //matirx 就是字符串矩阵; + //rows 和 cols 是其长度和宽度 + public boolean hasPath(char[] array, int rows, int cols, char[] str) { + if(rows==0){ + return false; + } + char[][] matrix = buildMatrix(array,rows,cols); + + m = rows; + n = cols; + visted = new boolean[m][n]; + + for(int i=0;i<m;i++){ + for(int j=0;j<n;j++){ + if(searchMatrix(matrix,str,0,i,j)){ + return true; + } + } + } + return false; + } + + @Test + public void test(){ + char[] matrix = "abcesfcsadee".toCharArray(); + char[] str="bcced".toCharArray(); + System.out.println(hasPath(matrix,3,4,str)); + } +} From 63872847f04ccfe02ed160868d20c824b9f6d3b3 Mon Sep 17 00:00:00 2001 From: DuHouAn <18351926682@163.com>
Date: 2019年8月14日 20:29:41 +0800
Subject: [PATCH 2/2] Java
---
 docs/AimForOffer/MyQueue.java &#124; 56 +++++++++++++
 docs/AimForOffer/ThreadSafeLRUCache.java &#124; 49 ++++++++++++
 docs/AimForOffer/TreeLinkNode.java &#124; 13 +++
 docs/AimForOffer/TreeNode.java &#124; 9 +++
 ...52347円273円223円347円202円271円_Important.java" &#124; 31 ++++++++
 ...63345円217円260円351円230円266円_Important.java" &#124; 32 ++++++++
 ...344円272円214円345円217円211円346円240円221円.java" &#124; 30 +++++++
 ...347円232円204円346円225円260円345円255円227円.java" &#124; 13 +--
 ...17346円225円260円345円255円227円_Important.java" &#124; 58 ++++++++++++++
 ...42347円251円272円346円240円274円_Important.java" &#124; 43 ++++++++++
 ...347円216円260円351円230円237円345円210円227円.java" &#124; 35 ++++++++
 ...42350円246円206円347円233円226円_Important.java" &#124; 37 +++++++++
 ...347円232円204円350円267円257円345円276円204円.java" &#124; 79 +------------------
 ...350円267円263円345円217円260円351円230円266円.java" &#124; 29 +++++++
 14 files changed, 424 insertions(+), 90 deletions(-)
 create mode 100644 docs/AimForOffer/MyQueue.java
 create mode 100644 docs/AimForOffer/ThreadSafeLRUCache.java
 create mode 100644 docs/AimForOffer/TreeLinkNode.java
 create mode 100644 docs/AimForOffer/TreeNode.java
 create mode 100644 "docs/AimForOffer/344円272円214円345円217円211円346円240円221円347円232円204円344円270円213円344円270円200円344円270円252円347円273円223円347円202円271円_Important.java"
 create mode 100644 "docs/AimForOffer/345円217円230円346円200円201円350円267円263円345円217円260円351円230円266円_Important.java"
 create mode 100644 "docs/AimForOffer/345円273円272円344円272円214円345円217円211円346円240円221円.java"
 create mode 100644 "docs/AimForOffer/346円227円213円350円275円254円346円225円260円347円273円204円347円232円204円346円234円200円345円260円217円346円225円260円345円255円227円_Important.java"
 create mode 100644 "docs/AimForOffer/346円233円277円346円215円242円347円251円272円346円240円274円_Important.java"
 create mode 100644 "docs/AimForOffer/347円224円250円344円270円244円344円270円252円346円240円210円345円256円236円347円216円260円351円230円237円345円210円227円.java"
 create mode 100644 "docs/AimForOffer/347円237円251円345円275円242円350円246円206円347円233円226円_Important.java"
 create mode 100644 "docs/AimForOffer/350円267円263円345円217円260円351円230円266円.java"
diff --git a/docs/AimForOffer/MyQueue.java b/docs/AimForOffer/MyQueue.java
new file mode 100644
index 0000000..59d933c
--- /dev/null
+++ b/docs/AimForOffer/MyQueue.java
@@ -0,0 +1,56 @@
+import java.util.Stack;
+
+/**
+ * Created by 18351 on 2019年7月23日.
+ */
+//使用两个栈实现队列的扩展
+public class MyQueue {
+ //用两个栈实现队列
+ Stack<integer> stack1 = new Stack<strong>();
+ Stack<integer> stack2 = new Stack<strong>();
+
+ //存储队列头元素
+ private int front; //方便后面的 peek() 操作
+
+ /** Initialize your data structure here. */
+ public MyQueue() {
+ stack1 = new Stack<strong>();
+ stack2 = new Stack<strong>();
+ }
+
+ public void push(int node) {
+ if(stack1.isEmpty()){
+ front = node;
+ }
+ stack1.push(node);
+ }
+
+ public int pop() {
+ if(stack2.isEmpty()){
+ while(!stack1.isEmpty()){
+ stack2.push(stack1.pop());
+ }
+ }
+ return stack2.pop();
+ }
+
+ public int peek(){
+ if(stack2.isEmpty()){
+ return front;
+ }
+ return stack2.peek();
+ }
+
+ public boolean empty(){
+ return (stack1.isEmpty()) && (stack2.isEmpty());
+ }
+
+ public static void main(String[] args) {
+ MyQueue queue = new MyQueue();
+ queue.push(1);
+ queue.push(2);
+ System.out.println(queue.peek()); // 返回 1
+ System.out.println(queue.pop()); // 返回 1
+ queue.empty(); // 返回 false
+ }
+}
diff --git a/docs/AimForOffer/ThreadSafeLRUCache.java b/docs/AimForOffer/ThreadSafeLRUCache.java
new file mode 100644
index 0000000..b725030
--- /dev/null
+++ b/docs/AimForOffer/ThreadSafeLRUCache.java
@@ -0,0 +1,49 @@
+import org.junit.Test;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+/**
+ * Created by 18351 on 2019年7月25日.
+ */
+public class ThreadSafeLRUCache<k, V> {
+ private static final int MAX_CAPACITY = 3;
+ private LinkedHashMap<k,v> linkedHashMap;
+
+ public ThreadSafeLRUCache(){
+ linkedHashMap = new LinkedHashMap(MAX_CAPACITY,0.75f,false){
+ @Override
+ protected boolean removeEldestEntry(Map.Entry eldest) {
+ return size()>MAX_CAPACITY;
+ }
+ };
+ }
+
+ public synchronized void put(K k,V v){
+ linkedHashMap.put(k,v);
+ }
+
+ public synchronized V get(K k){
+ return (V)linkedHashMap.get(k);
+ }
+
+ @Override
+ public String toString() {
+ StringBuilder sb=new StringBuilder();
+ for(Map.Entry<k,v> entry:linkedHashMap.entrySet())
+ sb.append(String.format("%s: %s\n", entry.getKey(), entry.getValue()));
+ return sb.toString();
+ }
+
+ @Test
+ public void test(){
+ ThreadSafeLRUCache<integer,string> cache=new ThreadSafeLRUCache<strong>();
+ cache.put(1, "a");
+ cache.put(2, "b");
+ cache.put(3, "c");
+ cache.get(1);
+ //LRU 键值1被访问过了,则最近最久未访问的就是2
+ cache.put(4, "d");
+ System.out.println(cache);
+ }
+}
diff --git a/docs/AimForOffer/TreeLinkNode.java b/docs/AimForOffer/TreeLinkNode.java
new file mode 100644
index 0000000..c277e9e
--- /dev/null
+++ b/docs/AimForOffer/TreeLinkNode.java
@@ -0,0 +1,13 @@
+/**
+ * Created by 18351 on 2019年7月23日.
+ */
+public class TreeLinkNode {
+ int val;
+ TreeLinkNode left = null;
+ TreeLinkNode right = null;
+ TreeLinkNode next = null;
+
+ TreeLinkNode(int val) {
+ this.val = val;
+ }
+}
diff --git a/docs/AimForOffer/TreeNode.java b/docs/AimForOffer/TreeNode.java
new file mode 100644
index 0000000..c9297d8
--- /dev/null
+++ b/docs/AimForOffer/TreeNode.java
@@ -0,0 +1,9 @@
+/**
+ * Created by 18351 on 2019年7月23日.
+ */
+public class TreeNode {
+ int val;
+ TreeNode left;
+ TreeNode right;
+ TreeNode(int x) { val = x; }
+}
diff --git "a/docs/AimForOffer/344円272円214円345円217円211円346円240円221円347円232円204円344円270円213円344円270円200円344円270円252円347円273円223円347円202円271円_Important.java" "b/docs/AimForOffer/344円272円214円345円217円211円346円240円221円347円232円204円344円270円213円344円270円200円344円270円252円347円273円223円347円202円271円_Important.java"
new file mode 100644
index 0000000..7a2963c
--- /dev/null
+++ "b/docs/AimForOffer/344円272円214円345円217円211円346円240円221円347円232円204円344円270円213円344円270円200円344円270円252円347円273円223円347円202円271円_Important.java"
@@ -0,0 +1,31 @@
+import java.util.Scanner;
+
+/**
+ * Created by 18351 on 2019年7月23日.
+ */
+public class 二叉树的下一个结点_Important {
+ //二叉树的下一个结点
+ public TreeLinkNode GetNext(TreeLinkNode pNode){
+ if(pNode==null){
+ return null;
+ }
+ if(pNode.right!=null){
+ //先判断 pNode 的右子树不为 null,
+ //pNode 的下一个结点就是 pNode 右子树的最左结点
+ TreeLinkNode node = pNode.right; //pNode 的右子树
+ while(node.left!=null){
+ node = node.left;
+ }
+ return node;
+ }else{ //否则,向上找第一个左连接指向的树包含该节点的祖先节点
+ while (pNode.next!=null){
+ TreeLinkNode parent = pNode.next;
+ if(parent.left==pNode){
+ return parent;
+ }
+ pNode = pNode.next;
+ }
+ }
+ return null;
+ }
+}
diff --git "a/docs/AimForOffer/345円217円230円346円200円201円350円267円263円345円217円260円351円230円266円_Important.java" "b/docs/AimForOffer/345円217円230円346円200円201円350円267円263円345円217円260円351円230円266円_Important.java"
new file mode 100644
index 0000000..ceaa998
--- /dev/null
+++ "b/docs/AimForOffer/345円217円230円346円200円201円350円267円263円345円217円260円351円230円266円_Important.java"
@@ -0,0 +1,32 @@
+import org.junit.Test;
+
+import java.util.Arrays;
+
+/**
+ * Created by 18351 on 2019年7月24日.
+ */
+public class 变态跳台阶_Important {
+ //动态规划思路:
+ //dp[i] 表示跳 i 阶台阶共有 dp[i] 中跳法
+ public int JumpFloorII(int target) {
+ int[] dp=new int[target+1];
+ //dp 数组数值初始化为 1
+ Arrays.fill(dp,1);
+
+ for(int i=2;i<=target;i++){ + for(int j=1;j<i;j++){ //每次青蛙可跳 j 步 + dp[i] = dp[i] + dp[j]; + } + } + return dp[target]; + } + + @Test + public void test(){ + //int target = 3; + //int target = 4; + //int target = 5; + int target = 6; + System.out.println(JumpFloorII(target)); + } +} diff --git "a/docs/AimForOffer/345円273円272円344円272円214円345円217円211円346円240円221円.java" "b/docs/AimForOffer/345円273円272円344円272円214円345円217円211円346円240円221円.java" new file mode 100644 index 0000000..12b9aa7 --- /dev/null +++ "b/docs/AimForOffer/345円273円272円344円272円214円345円217円211円346円240円221円.java" @@ -0,0 +1,30 @@ +/** + * Created by 18351 on 2019/7/23. + */ +public class 重建二叉树 { + public TreeNode reConstructBinaryTree(int [] pre, int [] in) { + return reConstructBinaryTree(pre,in,0,pre.length-1,0,in.length-1); + } + + private TreeNode reConstructBinaryTree(int[] pre,int[] in, + int preStart,int preEnd, + int inStart,int inEnd){ + if(preStart>preEnd &#124;&#124; inStart>inEnd){
+ return null;
+ }
+ TreeNode root = new TreeNode(pre[preStart]);
+
+ int index = -1;
+ for(int i=inStart;i<=inend;i++){ + if(in[i]==pre[preStart]){ + index = i; + break; + } + } + root.left = reConstructBinaryTree(pre,in, + preStart+1,preStart+(index-inStart),inStart,index-1); + root.right = reConstructBinaryTree(pre,in, + preStart+(index-inStart)+1,preEnd,index+1,inEnd); + return root; + } +} diff --git "a/docs/AimForOffer/346円225円260円347円273円204円344円270円255円351円207円215円345円244円215円347円232円204円346円225円260円345円255円227円.java" "b/docs/AimForOffer/346円225円260円347円273円204円344円270円255円351円207円215円345円244円215円347円232円204円346円225円260円345円255円227円.java" index 3dd4684..54c4855 100644 --- "a/docs/AimForOffer/346円225円260円347円273円204円344円270円255円351円207円215円345円244円215円347円232円204円346円225円260円345円255円227円.java" +++ "b/docs/AimForOffer/346円225円260円347円273円204円344円270円255円351円207円215円345円244円215円347円232円204円346円225円260円345円255円227円.java" @@ -1,10 +1,7 @@ -import org.junit.Test; - /** - * Created by DHA on 2019/7/22. + * Created by 18351 on 2019/7/23. */ public class 数组中重复的数字 { - //数组中重复的数字 public boolean duplicate(int numbers[],int length,int [] duplication) { for(int i=0;i<length;i++){ if(numbers[i]!=numbers[numbers[i]]){ @@ -27,12 +24,4 @@ private void swap(int[] nums,int i,int j){ nums[i] = nums[j]; nums[j] = tmp; } - - @Test - public void test(){ - int[] nums = {2,3,1,0,2,5,3}; - int[] duplication = new int[nums.length]; - System.out.println(duplicate(nums,nums.length,duplication)); - System.out.println(duplication[0]); - } } diff --git "a/docs/AimForOffer/346円227円213円350円275円254円346円225円260円347円273円204円347円232円204円346円234円200円345円260円217円346円225円260円345円255円227円_Important.java" "b/docs/AimForOffer/346円227円213円350円275円254円346円225円260円347円273円204円347円232円204円346円234円200円345円260円217円346円225円260円345円255円227円_Important.java" new file mode 100644 index 0000000..3c6b80d --- /dev/null +++ "b/docs/AimForOffer/346円227円213円350円275円254円346円225円260円347円273円204円347円232円204円346円234円200円345円260円217円346円225円260円345円255円227円_Important.java" @@ -0,0 +1,58 @@ +import org.junit.Test; + +/** + * Created by 18351 on 2019/7/25. + */ +public class 旋转数组的最小数字_Important { + //思路一: + //遍历,遇到前一个数大于后一个数,就返回后一个数 + //时间复杂度是 O(n) + public int minNumberInRotateArray_1(int [] array) { + if(array==null &#124;&#124; array.length==0){ + return 0; + } + if(array.length==1){ + return array[0]; + } + //此时数组中至少有 2 个元素 + int res = array[0]; + for(int i=1;i<array.length;i++){ + if(array[i-1]>array[i]){
+ res = array[i];
+ break;
+ }
+ }
+ return res;
+ }
+
+ //二分查找的变形:
+ //关键在于确定旋转数组在那一部分
+ public int minNumberInRotateArray(int [] array) {
+ if(array==null &#124;&#124; array.length==0){
+ return 0;
+ }
+ if(array.length==1){
+ return array[0];
+ }
+
+ int l=0;
+ int h=array.length-1;
+ while(l<h){ + int m = (h-l)/2+l; + if(array[m]<=array[h]){ //[l,m] 是旋转数组 + h = m; + }else{ //[m+1,h] 是旋转数组 + l =m+1; + } + } + return array[l]; + } + + + + @Test + public void test(){ + int[] nums={1,3,4,5}; + System.out.println(minNumberInRotateArray(nums)); + } +} diff --git "a/docs/AimForOffer/346円233円277円346円215円242円347円251円272円346円240円274円_Important.java" "b/docs/AimForOffer/346円233円277円346円215円242円347円251円272円346円240円274円_Important.java" new file mode 100644 index 0000000..88414c4 --- /dev/null +++ "b/docs/AimForOffer/346円233円277円346円215円242円347円251円272円346円240円274円_Important.java" @@ -0,0 +1,43 @@ +import org.junit.Test; + +/** + * Created by 18351 on 2019/7/22. + */ +public class 替换空格_Important { + public String replaceSpace(StringBuffer str) { + //P1 指向原来的 + //令 P1 指向字符串原来的末尾位置, + // P2 指向字符串现在的末尾位置。 + int P1 = str.length() - 1; + // ' ' 要转化为 '%20' 是需要额外的 2 个字符的位置 + for(int i=0;i<=p1;i++){ + char ch = str.charAt(i); + if(ch==' '){ + str.append(" "); + } + } + //P1 和 P2 从后向前遍历,当 P1 遍历到一个空格时, + //就需要令 P2 指向的位置依次填充 02%(注意是逆序的),否则就填充上 P1 指向字符的值。 + //从后向前遍是为了在改变 P2 所指向的内容时,不会影响到 P1 遍历原来字符串的内容。 + int P2=str.length()-1; + while(P1>=0 && P2>= P1){
+ char ch = str.charAt(P1);
+ if(ch==' '){
+ str.setCharAt(P2--,'0');
+ str.setCharAt(P2--,'2');
+ str.setCharAt(P2--,'%');
+ }else{
+ str.setCharAt(P2--,ch);
+ }
+ P1--;
+ }
+ return str.toString();
+ }
+
+ @Test
+ public void test(){
+ StringBuffer buffer = new StringBuffer();
+ buffer.append("A B C");
+ System.out.println(replaceSpace(buffer).toString());
+ }
+}
diff --git "a/docs/AimForOffer/347円224円250円344円270円244円344円270円252円346円240円210円345円256円236円347円216円260円351円230円237円345円210円227円.java" "b/docs/AimForOffer/347円224円250円344円270円244円344円270円252円346円240円210円345円256円236円347円216円260円351円230円237円345円210円227円.java"
new file mode 100644
index 0000000..50a4694
--- /dev/null
+++ "b/docs/AimForOffer/347円224円250円344円270円244円344円270円252円346円240円210円345円256円236円347円216円260円351円230円237円345円210円227円.java"
@@ -0,0 +1,35 @@
+import java.util.Stack;
+
+/**
+ * Created by 18351 on 2019年7月23日.
+ */
+public class 用两个栈实现队列 {
+ //用两个栈实现队列
+ Stack<integer> stack1 = new Stack<integer>();
+ Stack<integer> stack2 = new Stack<integer>();
+ int front; //用来记录第一个出栈元素
+
+ public void push(int node) {
+ if (stack1.isEmpty()){
+ front = node;
+ }
+ stack1.push(node);
+ }
+
+ public int pop() {
+ if(stack2.isEmpty()){
+ while(!stack1.isEmpty()){
+ stack2.push(stack1.pop());
+ }
+ }
+ return stack2.pop();
+ }
+
+ public static void main(String[] args) {
+ 用两个栈实现队列 q = new 用两个栈实现队列();
+ q.push(1);
+ q.push(2);
+ q.push(3);
+ q.pop();
+ }
+}
diff --git "a/docs/AimForOffer/347円237円251円345円275円242円350円246円206円347円233円226円_Important.java" "b/docs/AimForOffer/347円237円251円345円275円242円350円246円206円347円233円226円_Important.java"
new file mode 100644
index 0000000..45160bf
--- /dev/null
+++ "b/docs/AimForOffer/347円237円251円345円275円242円350円246円206円347円233円226円_Important.java"
@@ -0,0 +1,37 @@
+import org.junit.Test;
+
+import java.util.WeakHashMap;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Created by 18351 on 2019年7月23日.
+ */
+public class 矩形覆盖_Important {
+ //思路:
+ //n=1 时,1 种
+ //n=2 时,2 种
+ //n=3 时,3 种
+ //n=4 时,5 种
+ //f(n) = f(n-1) + f(n-2)
+ //注意:时间复杂度
+ //使用递归的方式时间复杂度较高
+ public int RectCover(int target) {
+ if (target==1){
+ return 1;
+ }
+ if(target==2){
+ return 2;
+ }
+
+ //TODO:循环方式替代递归方式
+ int pre1 = 1;
+ int pre2 = 2;
+ int res = 0;
+ for(int i=3;i<=target;i++){ + res = pre1 + pre2; + pre1 = pre2; + pre2 = res; + } + return res; + } +} diff --git "a/docs/AimForOffer/347円237円251円351円230円265円344円270円255円347円232円204円350円267円257円345円276円204円.java" "b/docs/AimForOffer/347円237円251円351円230円265円344円270円255円347円232円204円350円267円257円345円276円204円.java" index 37c982c..86f084f 100644 --- "a/docs/AimForOffer/347円237円251円351円230円265円344円270円255円347円232円204円350円267円257円345円276円204円.java" +++ "b/docs/AimForOffer/347円237円251円351円230円265円344円270円255円347円232円204円350円267円257円345円276円204円.java" @@ -1,83 +1,6 @@ -import org.junit.Test; - /** - * Created by DHA on 2019/7/25. + * Created by 18351 on 2019/7/25. */ public class 矩阵中的路径 { - private int m,n; //矩阵的长度、宽度 - private boolean[][] visted; //标记是否访问 - - private int[][] d={ - {0,1}, //向右 - {-1,0},//向上 - {0,-1},//向左 - {1,0} //向下 - }; - - private boolean inArea(int x,int y){ - return (x>=0 && x<m) && (y>=0 && y<n);
- }
-
- //从board[startx][starty]开始寻找word[index...word.ength()]
- private boolean searchMatrix(char[][] matrix, char[] str,int index,int startx,int starty){
- if(index==str.length-1){ //递归到最后一个元素,检测是否相等
- return matrix[startx][starty] == str[index];
- }
- if(matrix[startx][starty]==str[index]){
- visted[startx][starty] = true;
- for(int i=0;i<4;i++){
- int newX = startx+d[i][0];
- int newY = starty+d[i][1];
- if(inArea(newX,newY) && !visted[newX][newY]){
- if(searchMatrix(matrix,str,index+1,newX,newY)){
- return true;
- }
- }
- }
- visted[startx][starty] =false;
- }
- return false;
- }
-
- //构建二维矩阵
- private char[][] buildMatrix(char[] array, int rows, int cols){
- //根据char[] matrix, rows, cols 构建二维的矩阵
- char[][] matrix = new char[rows][cols];
- int index=0;
- for(int i=0;i<rows;i++) {
- for (int j = 0; j < cols; j++) {
- matrix[i][j] = array[index++];
- }
- }
- return matrix;
- }
-
- //matirx 就是字符串矩阵;
- //rows 和 cols 是其长度和宽度
- public boolean hasPath(char[] array, int rows, int cols, char[] str) {
- if(rows==0){
- return false;
- }
- char[][] matrix = buildMatrix(array,rows,cols);
-
- m = rows;
- n = cols;
- visted = new boolean[m][n];
-
- for(int i=0;i<m;i++){
- for(int j=0;j<n;j++){
- if(searchMatrix(matrix,str,0,i,j)){
- return true;
- }
- }
- }
- return false;
- }
 
- @Test
- public void test(){
- char[] matrix = "abcesfcsadee".toCharArray();
- char[] str="bcced".toCharArray();
- System.out.println(hasPath(matrix,3,4,str));
- }
 }
diff --git "a/docs/AimForOffer/350円267円263円345円217円260円351円230円266円.java" "b/docs/AimForOffer/350円267円263円345円217円260円351円230円266円.java"
new file mode 100644
index 0000000..4761874
--- /dev/null
+++ "b/docs/AimForOffer/350円267円263円345円217円260円351円230円266円.java"
@@ -0,0 +1,29 @@
+import org.junit.Test;
+
+/**
+ * Created by 18351 on 2019/7/24.
+ */
+public class 跳台阶 {
+ //思路:target 是指 n 节级台阶
+ //n = 1, 有 1 种跳法
+ //n = 2, 有 2 种跳法
+ //n = 3, 有 3 种跳法
+ public int JumpFloor(int target) {
+ if(target<=2){
+ return target;
+ }
+ int pre1 = 1;
+ int pre2 = 2;
+ for(int i=3;i<=target;i++){
+ int next = pre1 + pre2;
+ pre1 = pre2;
+ pre2 = next;
+ }
+ return pre2;
+ }
+
+ @Test
+ public void test(){
+ System.out.println(JumpFloor(5));
+ }
+}
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