Submission #29917

#	Time	Username	Problem	Language	Result	Execution time	Memory
29917		PrOAhMeT	007 (CEOI14_007)	C++14	0 / 100	363 ms	18168 KiB

007

#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define LL long long
#define st first
#define nd second
#define endl '\n'
using namespace std;

const int MAXN=200005;
int n,m,dis[2][MAXN],s,d,a,b,t,tt;
vector<int> v[MAXN];

void bfs(int start,int wait,int u) {

	memset(dis[u],-1,sizeof dis[u]);
	queue<int> q;
	dis[u][start]=0;
	int x,y;
	q.push(start);
	while(!q.empty()) {
		x=q.front();
		q.pop();
		for(int i=0;i<v[x].size();++i) {
			y=v[x][i];
			if(dis[u][y]==-1) {
				dis[u][y]=dis[u][x]+1;
				q.push(y);
			}
		}
	}

}

int main() {

	scanf("%d %d",&n,&m);
	scanf("%d %d %d %d",&s,&d,&a,&b);
	for(int i=0;i<m;++i) {
		scanf("%d %d",&t,&tt);
		v[t].pb(tt);
		v[tt].pb(t);
	}
	int l=0,r=n,ans=-1,md;
	bfs(d,0,1);
	bfs(s,0,0);
	if(dis[0][a]>dis[1][a]||dis[0][b]>dis[1][b])
		cout<<-1<<endl;
	else {
		cout<<min(dis[1][a]-dis[0][a],dis[1][b]-dis[0][b])<<endl;
	}

}

Compilation message (stderr)

007.cpp: In function 'void bfs(int, int, int)':
007.cpp:25:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<v[x].size();++i) {
                ^
007.cpp: In function 'int main()':
007.cpp:45:6: warning: unused variable 'l' [-Wunused-variable]
  int l=0,r=n,ans=-1,md;
      ^
007.cpp:45:10: warning: unused variable 'r' [-Wunused-variable]
  int l=0,r=n,ans=-1,md;
          ^
007.cpp:45:14: warning: unused variable 'ans' [-Wunused-variable]
  int l=0,r=n,ans=-1,md;
              ^
007.cpp:45:21: warning: unused variable 'md' [-Wunused-variable]
  int l=0,r=n,ans=-1,md;
                     ^
007.cpp:38:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n,&m);
                      ^
007.cpp:39:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %d %d",&s,&d,&a,&b);
                                  ^
007.cpp:41:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d",&t,&tt);
                        ^

• Subtask 1: 0 / 30
• Subtask 2: 0 / 70