Submission #1591871

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;


#define INF 1000000005
typedef pair<int, int> P;


int N, Q;
vector< vector<int> > edges(100005);
int d[100005];

 
void dijkstra(int x) {
	for(int i=0;i<N+1;i++) d[i] = INF;
	priority_queue< P, vector<P>, greater<P> > q;
	d[x] = 0;
	q.push(P(0, x));
	while(!q.empty()){
		P p = q.top();
		q.pop();
		int dist = p.first;
		int u = p.second;
		for(int i = 0; i < edges[u].size(); i++){
			int v = edges[u][i];
			if(dist > d[v]) continue;
			if(d[v] > d[u] + 1) {
				d[v] = d[u] + 1;
				q.push(P(d[v], v));
			}
		}
	}
}
 
 
int main() {
	scanf("%d", &N);
	for(int i=0;i<N-1;i++){
		int u, v;
		scanf("%d %d", &u, &v);
		edges[u].push_back(v);
		edges[v].push_back(u);
	}
	
	scanf("%d", &Q);
	for(int i=0;i<Q;i++){
		int u, v;
		scanf("%d %d", &u, &v);
		dijkstra(u);
		printf("%d\n", d[v] + 1);
	}
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:37:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
                 ^
./Main.cpp:40:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &u, &v);
                         ^
./Main.cpp:45:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &Q);
                 ^
./Main.cpp:48:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &u, &v);
                         ^

Judge Result