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Commit 27f5811

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Merge pull request #9 from joney000/feature/jassi/BinaryLifting
Feature/jassi/binary lifting
2 parents 31992f5 + f577aab commit 27f5811

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4 files changed

+78
-22
lines changed

4 files changed

+78
-22
lines changed

‎Algorithms/BFS_GRID.java

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* Platform : N/A
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*
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*/
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/* The Main Class */
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public class A {
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private InputStream inputStream ;

‎Algorithms/BinaryLifting.java

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import java.util.LinkedList;
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/**
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* Time: O(N log N + Q * log N), each query is answered in log N time. Space: O(N log N)
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* Use:
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* Your BinaryLifting object will be instantiated and called as such:
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* BinaryLifting obj = new BinaryLifting(n, parent);
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* int param_1 = obj.getKthAncestor(node,k);
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* ref: https://leetcode.com/problems/kth-ancestor-of-a-tree-node/ and https://www.youtube.com/watch?v=oib-XsjFa-M
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*/
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class BinaryLifting {
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// preprocess
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// O(N log N)
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// precompute the answer for power of 2
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private int[][] atLevel; // atLevel[nodeId][level] means what is the predecessor at 2^level higher
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private int MAX_LOG = 0;
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boolean vis[];
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public BinaryLifting(int n, int[] parent) {
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MAX_LOG = 0;
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vis = new boolean[n];
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while(n >= (1 << MAX_LOG)){
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MAX_LOG++;
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}
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atLevel = new int[n][MAX_LOG];
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for(int nodeId = 0; nodeId < n; nodeId++){
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for(int level = 0; level < MAX_LOG; level++){
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atLevel[nodeId][level] = -1;
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}
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}
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for(int nodeId = 1; nodeId <= n - 1; nodeId++){
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if(vis[nodeId])continue;
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LinkedList<Integer> unVisited = new LinkedList<Integer>(); // linked list as a stack for unvisited node
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int currentNode = nodeId;
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while(currentNode != -1 && !vis[currentNode]){
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unVisited.addLast(currentNode);
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currentNode = parent[currentNode];
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}
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while(!unVisited.isEmpty()){
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int topUnvisitedNode = unVisited.removeLast();
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atLevel[topUnvisitedNode][0] = parent[topUnvisitedNode];
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for(int level = 1; level <= MAX_LOG - 1; level++){
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if(atLevel[topUnvisitedNode][level - 1] != -1){
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atLevel[topUnvisitedNode][level] = atLevel[atLevel[topUnvisitedNode][level - 1]][level - 1];
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}else{
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break;
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}
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}
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vis[topUnvisitedNode] = true;
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}
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}
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}
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public int getKthAncestor(int node, int k) {
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int kthAncestor = node;
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for(int level = MAX_LOG - 1; level >= 0; level--){ // at ancestor at 2^level
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if((k & (1 << level)) > 0){ // check if ith bit is set
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// every numer can be represented by sum of power of 2
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kthAncestor = atLevel[kthAncestor][level];
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if(kthAncestor == -1){
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break;
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}
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}
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}
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return kthAncestor;
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}
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}
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‎Algorithms/SuffixArray,HashingSeive.java

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*
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*/
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/* The Main Class */
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class A{
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private InputStream inputStream ;
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private OutputStream outputStream ;
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private FastReader in ;
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private PrintWriter out ;
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private PrintWriter out ;
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/*
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Overhead [Additional Temporary Strorage] but provides memory reusibility for multiple test cases.
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‎Solution.java

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in = new FastReader(inputStream);
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out = new PrintWriter(outputStream);
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}
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final int MAXN = (int)1e3 + 1;
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int [][]mat = new int[MAXN][MAXN];
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int [][]matrix = new int[MAXN][MAXN];
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void run()throws Exception{
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int tests = i();
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for(int t = 1; t <= tests; t++){
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for(int testCase = 1; testCase <= tests; testCase++){
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out.write("Case #"+testCase+": ");
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int n = i();
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String s = s();
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// solve cool things here
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long ans = 0L;
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out.write("Case #"+t+": ");
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for(int i = 1; i <= s.length(); i++){
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if(s.charAt(i - 1) == 'S')out.write("E");
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else out.write("S");
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}
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out.write("\n");
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out.write(""+ans+"\n");
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}
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}
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boolean isContain4(String a){
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String key = ""+a;
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for(int pos = 1; pos <= key.length(); pos++){
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if(key.charAt(pos - 1)=='4')return true;
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}
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return false;
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}
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void clear(){
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void clear(){
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// Todo: implementation of clearing the shared memory for each test case
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}
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long gcd(long a, long b){

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