题目：1971. 寻找图中是否存在路径
思路
并查集
代码
class Solution {
private:int n = 200005;int father[200005] = {0};void init(){int i;for(i = 0; i < n; i++){father[i] = i;}}int find(int u){if(u == father[u]){return u;}else{return father[u] = find(father[u]);}}bool isSame(int u, int v){u = find(u);v = find(v);return u == v;}// 加入 u -> vvoid join(int u, int v){u = find(u);v = find(v);if(u == v){return;}else{father[u] = v;}}public:bool validPath(int n, vector<vector<int>>& edges, int source, int destination) {int i, u, v;init();for(i = 0; i < edges.size(); i++){join(edges[i][0], edges[i][1]);}return isSame(source, destination);}
};
注意数组不要越界了，validPath函数里n是节点个数，edge长度是边的个数，可不一定相等哦！
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