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Merge pull request #619 from LetMeFly666/3249
添加问题“3249.统计好节点的数目”的代码和题解
2 parents 8472d91 + 043fd35 commit 9376adc

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‎Codes/3249-count-the-number-of-good-nodes.cpp‎

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/*
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* @Author: LetMeFly
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* @Date: 2024-11-14 12:49:44
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* @LastEditors: LetMeFly.xyz
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* @LastEditTime: 2024-11-14 12:55:36
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*/
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#ifdef _WIN32
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#include "_[1,2]toVector.h"
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#endif
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class Solution {
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private:
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int ans;
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vector<vector<int>> graph;
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int dfs(int root, int parent=-1) {
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int cnt = 1;
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int oneChild = 0;
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bool thisNodeOk = true;
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for (int nextNode : graph[root]) {
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if (nextNode == parent) {
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continue;
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}
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int nextCnt = dfs(nextNode, root);
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cnt += nextCnt;
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if (oneChild && nextCnt != oneChild) {
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thisNodeOk = false;
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}
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oneChild = nextCnt;
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}
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if (thisNodeOk) {
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ans++;
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}
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return cnt;
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}
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public:
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int countGoodNodes(vector<vector<int>>& edges) {
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ans = 0;
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graph.resize(edges.size() + 1);
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for (vector<int>& edge : edges) {
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graph[edge[0]].push_back(edge[1]);
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graph[edge[1]].push_back(edge[0]);
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}
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dfs(0);
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return ans;
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}
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};

‎Codes/3249-count-the-number-of-good-nodes.go‎

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/*
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* @Author: LetMeFly
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* @Date: 2024-11-14 13:15:02
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* @LastEditors: LetMeFly.xyz
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* @LastEditTime: 2024-11-14 13:24:43
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*/
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package main
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// import "fmt"
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func countGoodNodes(edges [][]int) (ans int) {
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graph := make([][]int, len(edges) + 1)
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for _, edge := range edges {
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graph[edge[0]] = append(graph[edge[0]], edge[1])
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graph[edge[1]] = append(graph[edge[1]], edge[0])
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}
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var dfs func(int, int) int
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dfs = func(thisNode, lastNode int) int {
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// fmt.Println(thisNode, lastNode)
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cnt, oneChild, ok := 1, 0, true
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for _, nextNode := range graph[thisNode] {
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if nextNode == lastNode {
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continue
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}
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thisChild := dfs(nextNode, thisNode)
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cnt += thisChild
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if oneChild == 0 {
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oneChild = thisChild
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} else if oneChild != thisChild {
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ok = false
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}
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}
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if ok {
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ans++
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}
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return cnt
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}
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dfs(0, -1)
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return ans
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}

‎Codes/3249-count-the-number-of-good-nodes.java‎

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/*
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* @Author: LetMeFly
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* @Date: 2024-11-14 13:00:47
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* @LastEditors: LetMeFly.xyz
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* @LastEditTime: 2024-11-14 13:14:26
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*/
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.List;
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class Solution {
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private List<Integer>[] graph;
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private int ans;
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private int dfs(int thisNode, int lastNode) {
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int cnt = 1;
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int oneChild = 0;
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boolean ok = true;
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for (int nextChilld : graph[thisNode]) {
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if (nextChilld == lastNode) {
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continue;
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}
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int thisChild = dfs(nextChilld, thisNode);
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cnt += thisChild;
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if (oneChild == 0) {
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oneChild = thisChild;
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} else if (oneChild != thisChild) {
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ok = false;
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}
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}
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if (ok) {
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ans++;
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}
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return cnt;
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}
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public int countGoodNodes(int[][] edges) {
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ans = 0;
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graph = new ArrayList[edges.length + 1];
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Arrays.setAll(graph, i -> new ArrayList<>());
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for (int[] edge : edges) {
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graph[edge[0]].add(edge[1]);
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graph[edge[1]].add(edge[0]);
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}
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dfs(0, -1);
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return ans;
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}
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}

‎Codes/3249-count-the-number-of-good-nodes.py‎

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'''
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Author: LetMeFly
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Date: 2024-11-14 12:56:25
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LastEditors: LetMeFly.xyz
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LastEditTime: 2024-11-14 13:00:23
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'''
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from typing import List
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class Solution:
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def dfs(self, thisNode: int, parentNode: int=-1) -> int:
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cnt, oneChild, ok = 1, 0, True
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for nextNode in self.graph[thisNode]:
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if nextNode == parentNode:
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continue
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nextChild = self.dfs(nextNode, thisNode)
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cnt += nextChild
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if not oneChild:
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oneChild = nextChild
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elif oneChild != nextChild:
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ok = False
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if ok:
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self.ans += 1
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return cnt
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def countGoodNodes(self, edges: List[List[int]]) -> int:
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self.graph = [[] for _ in range(len(edges) + 1)]
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for x, y in edges:
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self.graph[x].append(y)
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self.graph[y].append(x)
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self.ans = 0
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self.dfs(0)
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return self.ans

‎README.md‎

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|3222.求出硬币游戏的赢家|简单|<a href="https://leetcode.cn/problems/find-the-winning-player-in-coin-game/solutions/" target="_blank">题目地址</a>|<a href="https://blog.letmefly.xyz/2024/11/05/LeetCode%203222.%E6%B1%82%E5%87%BA%E7%A1%AC%E5%B8%81%E6%B8%B8%E6%88%8F%E7%9A%84%E8%B5%A2%E5%AE%B6/" target="_blank">题解地址</a>|<a href="https://letmefly.blog.csdn.net/article/details/143501415" target="_blank">CSDN题解</a>|<a href="https://leetcode.cn/problems/find-the-winning-player-in-coin-game/solutions/2977629/letmefly-3222qiu-chu-ying-bi-you-xi-de-y-08j3/" target="_blank">LeetCode题解</a>|
720720
|3226.使两个整数相等的位更改次数|简单|<a href="https://leetcode.cn/problems/number-of-bit-changes-to-make-two-integers-equal/solutions/" target="_blank">题目地址</a>|<a href="https://blog.letmefly.xyz/2024/11/02/LeetCode%203226.%E4%BD%BF%E4%B8%A4%E4%B8%AA%E6%95%B4%E6%95%B0%E7%9B%B8%E7%AD%89%E7%9A%84%E4%BD%8D%E6%9B%B4%E6%94%B9%E6%AC%A1%E6%95%B0/" target="_blank">题解地址</a>|<a href="https://letmefly.blog.csdn.net/article/details/143448117" target="_blank">CSDN题解</a>|<a href="https://leetcode.cn/problems/number-of-bit-changes-to-make-two-integers-equal/solutions/2974558/letmefly-3226shi-liang-ge-zheng-shu-xian-j01h/" target="_blank">LeetCode题解</a>|
721721
|3242.设计相邻元素求和服务|简单|<a href="https://leetcode.cn/problems/design-neighbor-sum-service/solutions/" target="_blank">题目地址</a>|<a href="https://blog.letmefly.xyz/2024/11/11/LeetCode%203242.%E8%AE%BE%E8%AE%A1%E7%9B%B8%E9%82%BB%E5%85%83%E7%B4%A0%E6%B1%82%E5%92%8C%E6%9C%8D%E5%8A%A1/" target="_blank">题解地址</a>|<a href="https://letmefly.blog.csdn.net/article/details/143698347" target="_blank">CSDN题解</a>|<a href="https://leetcode.cn/problems/design-neighbor-sum-service/solutions/2985408/letmefly-3242she-ji-xiang-lin-yuan-su-qi-mc7m/" target="_blank">LeetCode题解</a>|
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|3249.统计好节点的数目|中等|<a href="https://leetcode.cn/problems/count-the-number-of-good-nodes/solutions/" target="_blank">题目地址</a>|<a href="https://blog.letmefly.xyz/2024/11/14/LeetCode%203249.%E7%BB%9F%E8%AE%A1%E5%A5%BD%E8%8A%82%E7%82%B9%E7%9A%84%E6%95%B0%E7%9B%AE/" target="_blank">题解地址</a>|<a href="https://letmefly.blog.csdn.net/article/details/143768804" target="_blank">CSDN题解</a>|<a href="https://leetcode.cn/problems/count-the-number-of-good-nodes/solutions/2988295/letmefly-3249tong-ji-hao-jie-dian-de-shu-zojm/" target="_blank">LeetCode题解</a>|
722723
|3254.长度为K的子数组的能量值I|中等|<a href="https://leetcode.cn/problems/find-the-power-of-k-size-subarrays-i/solutions/" target="_blank">题目地址</a>|<a href="https://blog.letmefly.xyz/2024/11/06/LeetCode%203254.%E9%95%BF%E5%BA%A6%E4%B8%BAK%E7%9A%84%E5%AD%90%E6%95%B0%E7%BB%84%E7%9A%84%E8%83%BD%E9%87%8F%E5%80%BCI/" target="_blank">题解地址</a>|<a href="https://letmefly.blog.csdn.net/article/details/143575677" target="_blank">CSDN题解</a>|<a href="https://leetcode.cn/problems/find-the-power-of-k-size-subarrays-i/solutions/2979562/letmefly-3254chang-du-wei-k-de-zi-shu-zu-iu8u/" target="_blank">LeetCode题解</a>|
723724
|3255.长度为K的子数组的能量值II|中等|<a href="https://leetcode.cn/problems/find-the-power-of-k-size-subarrays-ii/solutions/" target="_blank">题目地址</a>|<a href="https://blog.letmefly.xyz/2024/11/07/LeetCode%203255.%E9%95%BF%E5%BA%A6%E4%B8%BAK%E7%9A%84%E5%AD%90%E6%95%B0%E7%BB%84%E7%9A%84%E8%83%BD%E9%87%8F%E5%80%BCII/" target="_blank">题解地址</a>|<a href="https://letmefly.blog.csdn.net/article/details/143591327" target="_blank">CSDN题解</a>|<a href="https://leetcode.cn/problems/find-the-power-of-k-size-subarrays-ii/solutions/2980432/letmefly-3255chang-du-wei-k-de-zi-shu-zu-rags/" target="_blank">LeetCode题解</a>|
724725
|3258.统计满足K约束的子字符串数量I|简单|<a href="https://leetcode.cn/problems/count-substrings-that-satisfy-k-constraint-i/solutions/" target="_blank">题目地址</a>|<a href="https://blog.letmefly.xyz/2024/11/12/LeetCode%203258.%E7%BB%9F%E8%AE%A1%E6%BB%A1%E8%B6%B3K%E7%BA%A6%E6%9D%9F%E7%9A%84%E5%AD%90%E5%AD%97%E7%AC%A6%E4%B8%B2%E6%95%B0%E9%87%8FI/" target="_blank">题解地址</a>|<a href="https://letmefly.blog.csdn.net/article/details/143726399" target="_blank">CSDN题解</a>|<a href="https://leetcode.cn/problems/count-substrings-that-satisfy-k-constraint-i/solutions/2986598/letmefly-3258tong-ji-man-zu-k-yue-shu-de-fs44/" target="_blank">LeetCode题解</a>|

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