@@ -42,6 +42,12 @@ nums[0] = [<em><strong>3</strong></em>,1,2,<em><strong>4</strong></em>,5],nums
4242
4343<!-- 这里可写通用的实现逻辑 -->
4444
45+ ** 方法一:计数**
46+ 47+ 遍历数组 ` nums ` ,对于每个数组 ` arr ` ,统计数组 ` arr ` 中每个数字出现的次数,然后遍历计数数组,统计出现次数等于数组 ` nums ` 的长度的数字,即为答案。
48+ 49+ 时间复杂度 $O(N),ドル空间复杂度 $O(1000)$。其中 $N$ 为数组 ` nums ` 中数字的总数。
50+ 4551<!-- tabs:start -->
4652
4753### ** Python3**
@@ -52,11 +58,24 @@ nums[0] = [<em><strong>3</strong></em>,1,2,<em><strong>4</strong></em>,5],nums
5258class Solution :
5359 def intersection (self nums : List[List[int ]]) -> List[int ]:
5460 cnt = [0 ] * 1001
55- for num in nums:
56- for v in num:
57- cnt[v] += 1
58- n = len (nums)
59- return [i for i, v in enumerate (cnt) if v == n]
61+ for arr in nums:
62+ for x in arr:
63+ cnt[x] += 1
64+ return [x for x, v in enumerate (cnt) if v == len (nums)]
65+ ```
66+ 67+ ``` python
68+ class Solution :
69+ def intersection (self nums : List[List[int ]]) -> List[int ]:
70+ cnt = Counter()
71+ ans = []
72+ for arr in nums:
73+ for x in arr:
74+ cnt[x] += 1
75+ if cnt[x] == len (nums):
76+ ans.append(x)
77+ ans.sort()
78+ return ans
6079```
6180
6281### ** Java**
@@ -67,34 +86,37 @@ class Solution:
6786class Solution {
6887 public List<Integer > intersection (int [][] nums ) {
6988 int [] cnt = new int [1001 ];
70- for (int [] num : nums) {
71- for (int i : num ) {
72- cnt[i] ++ ;
89+ for (var arr : nums) {
90+ for (int x : arr ) {
91+ ++ cnt[x] ;
7392 }
7493 }
7594 List<Integer > ans = new ArrayList<> ();
76- for (int i = 1 ; i <= 1000 ; i ++ ) {
77- if (cnt[i ] == nums. length) {
78- ans. add(i );
95+ for (int x = 0 ; x < 1001 ; ++ x ) {
96+ if (cnt[x ] == nums. length) {
97+ ans. add(x );
7998 }
8099 }
81100 return ans;
82101 }
83102}
84103```
85104
86- ### ** TypeScript**
87- 88- ``` ts
89- function intersection(nums : number [][]): number [] {
90- const = nums .length ;
91- let ans = nums [0 ];
92- for (let i = 1 ; i < n && ans .length ; i ++ ) {
93- const = new Set (nums [i ]);
94- // get intersect
95- ans = ans .filter (v => cur .has (v ));
105+ ``` java
106+ class Solution {
107+ public List<Integer > intersection (int [][] nums ) {
108+ Map<Integer , Integer > cnt = new HashMap<> ();
109+ List<Integer > ans = new ArrayList<> ();
110+ for (var arr : nums) {
111+ for (int x : arr) {
112+ if (cnt. merge(x, 1 , Integer :: sum) == nums. length) {
113+ ans. add(x);
114+ }
115+ }
116+ }
117+ Collections . sort(ans);
118+ return ans;
96119 }
97- return ans .sort ((a , b ) => a - b );
98120}
99121```
100122
@@ -104,15 +126,37 @@ function intersection(nums: number[][]): number[] {
104126class Solution {
105127public:
106128 vector<int > intersection(vector<vector<int >>& nums) {
107- vector<int > cnt(1001);
108- for (auto& num : nums)
109- for (int v : num)
110- ++cnt[ v] ;
111- int n = nums.size();
129+ int cnt[ 1001] {};
130+ for (auto& arr : nums) {
131+ for (int& x : arr) {
132+ ++cnt[ x] ;
133+ }
134+ }
135+ vector<int > ans;
136+ for (int x = 0; x < 1001; ++x) {
137+ if (cnt[ x] == nums.size()) {
138+ ans.push_back(x);
139+ }
140+ }
141+ return ans;
142+ }
143+ };
144+ ```
145+
146+ ```cpp
147+ class Solution {
148+ public:
149+ vector<int> intersection(vector<vector<int>>& nums) {
150+ unordered_map<int, int> cnt;
112151 vector<int> ans;
113- for (int i = 1; i < 1001; ++i)
114- if (cnt[ i] == n)
115- ans.push_back(i);
152+ for (auto& arr : nums) {
153+ for (int& x : arr) {
154+ if (++cnt[x] == nums.size()) {
155+ ans.push_back(x);
156+ }
157+ }
158+ }
159+ sort(ans.begin(), ans.end());
116160 return ans;
117161 }
118162};
@@ -121,20 +165,71 @@ public:
121165### ** Go**
122166
123167``` go
124- func intersection(nums [][]int) []int {
125- cnt := make([ ]int, 1001)
126- for _, num := range nums {
127- for _, v := range num {
128- cnt[v ]++
168+ func intersection (nums [][]int ) ( ans []int ) {
169+ cnt := [ 1001 ]int {}
170+ for _ , arr := range nums {
171+ for _ , x := range arr {
172+ cnt[x ]++
129173 }
130174 }
131- var ans []int
132- for i, v := range cnt {
175+ for x , v := range cnt {
133176 if v == len (nums) {
134- ans = append(ans, i )
177+ ans = append (ans, x )
135178 }
136179 }
137- return ans
180+ return
181+ }
182+ ```
183+ 184+ ``` go
185+ func intersection (nums [][]int ) (ans []int ) {
186+ cnt := map [int ]int {}
187+ for _ , arr := range nums {
188+ for _ , x := range arr {
189+ cnt[x]++
190+ if cnt[x] == len (nums) {
191+ ans = append (ans, x)
192+ }
193+ }
194+ }
195+ sort.Ints (ans)
196+ return
197+ }
198+ ```
199+ 200+ ### ** TypeScript**
201+ 202+ ``` ts
203+ function intersection(nums : number [][]): number [] {
204+ const = new Array (1001 ).fill (0 );
205+ for (const of nums ) {
206+ for (const of arr ) {
207+ cnt [x ]++ ;
208+ }
209+ }
210+ const : number [] = [];
211+ for (let x = 0 ; x < 1001 ; x ++ ) {
212+ if (cnt [x ] === nums .length ) {
213+ ans .push (x );
214+ }
215+ }
216+ return ans ;
217+ }
218+ ```
219+ 220+ ``` ts
221+ function intersection(nums : number [][]): number [] {
222+ const = new Array (1001 ).fill (0 );
223+ const : number [] = [];
224+ for (const of nums ) {
225+ for (const of arr ) {
226+ if (++ cnt [x ] == nums .length ) {
227+ ans .push (x );
228+ }
229+ }
230+ }
231+ ans .sort ((a , b ) => a - b );
232+ return ans ;
138233}
139234```
140235
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