为啥过6/11？，预期21565，实际输出21566

#include <iostream> #include <bits/stdc++.h> using namespace std;  bool track(unordered_map<int, vector<int>>& tree, string& color, int n1, int n2, int& r, int& g, int& b){     if(color[n1 - 1] == 'r') r++;     else if(color[n1 - 1] == 'g') g++;     else b++;     if(r&&g&&b) return true;     bool rgb = false;      for(int i = 0; i < tree[n1].size(); i++){         if(tree[n1][i] == n2) continue;         else{             if(color[tree[n1][i] - 1] == 'r') r++;             else if(color[tree[n1][i] - 1] == 'g') g++;             else b++;         }         rgb |= track(tree, color, tree[n1][i], n1, r, g, b);     }     return rgb; }  bool check(unordered_map<int, vector<int>>& tree, string& color,int n1, int n2){     int r=0, g=0, b=0;     return track(tree, color, n1, n2, r, g, b); }  int main() {     int n;     while (cin >> n) { // 注意 while 处理多个 case         string color;         cin >> color;         unordered_map<int, vector<int>> tree;                 int f, c;         vector<vector<int>> edge;         for(int i = 0; i < n; i++){             cin >> f >> c;             edge.push_back({f, c});             tree[f].push_back(c);             tree[c].push_back(f);         }         int res = 0;         for(int i = 0; i < edge.size(); i++){             if(check(tree, color, edge[i][0], edge[i][1]) && check(tree, color, edge[i][1], edge[i][0])){                 res++;             }         }         cout << res << endl;     } } // 64 位输出请用 printf("%lld")

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