P5651 基础最短路练习题40求调

#include <bits/stdc++.h>
#define ll long long
#define c1 cout << 1 << " "
#define cen cout << endl
using namespace std;
void f(){

}
vector<pair<int,int> > v[100009];
long long dis[100009]={0};
bool vis[100009]={0};
void dfs(int i,long long sum){
	dis[i]=sum;
	for(int j=0;j<v[i].size();j++){
		if(!vis[j]){
			vis[j]=1;
			dfs(v[i][j].first,(i==0?v[i][j].second:sum^v[i][j].second));
			vis[j]=0;
		}
	}
}
int main(){
	int n,m,q;
	cin >> n >> m >> q;
	int x,y,u;
	for(int i=0;i<m;i++){
		cin >> x >> y >> u;
		x--;y--;
		v[x].push_back({y,u});
		v[y].push_back({x,u});
	}
	dfs(0,0);
	while(q--){
		cin >> x >> y;
		x--;y--;
		cout << (dis[x]^dis[y]) << endl;
	}
	return 0;
}