Submission #58270

#	Time	Username	Problem	Language	Result	Execution time	Memory
58270		evpipis	007 (CEOI14_007)	C++14	0 / 100	1090 ms	15820 KiB

007

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

#define fi first
#define se second
#define mp make_pair
#define pb push_back
typedef long long ll;
typedef pair<int, int> ii;

const int len = 2e5+5, inf = 1e9;
int dis[len], tim[len];
int n, m, s1, s2, t1, t2;
queue<int> myq;
vector<int> adj[len];

void bfs(int st){
    for (int i = 1; i <= n; i++)
        dis[i] = -1;

    dis[st] = 0, myq.push(st);
    while (!myq.empty()){
        int u = myq.front();
        myq.pop();

        for (int j = 0; j < adj[u].size(); j++){
            int v = adj[u][j];
            if (dis[v] == -1)
                dis[v] = dis[u]+1, myq.push(v);
        }
    }
}

int main(){
    scanf("%d %d %d %d %d %d", &n, &m, &s1, &s2, &t1, &t2);
    for (int i = 0; i < m; i++){
        int a, b;
        scanf("%d %d", &a, &b);
        adj[a].pb(b);
        adj[b].pb(a);
    }

    int a1, a2, b1, b2, w1, w2;
    bfs(t1);
    a1 = dis[s1], b1 = dis[s2], w1 = b1-a1;

    bfs(t2);
    a2 = dis[s1], b2 = dis[s2], w2 = b2-a2;

    if (w1 > w2)
        swap(a1, a2), swap(b1, b2), swap(w1, w2);

    if (b1 == b2 && a1 == a2)
        while (true){}
    else
        printf("%d\n", w1);
    return 0;
}

/*
9 10
9 8 1 2
1 2
2 3
3 1
2 4
4 5
5 2
5 7
7 6
7 8
7 9

6 6
1 2 3 4
1 5
5 6
6 3
6 4
1 2
3 4

6 7
5 6 1 2
6 3
1 2
1 3
2 3
1 5
2 4
5 4
*/

Compilation message (stderr)

007.cpp: In function 'void bfs(int)':
007.cpp:26:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int j = 0; j < adj[u].size(); j++){
                         ~~^~~~~~~~~~~~~~~
007.cpp: In function 'int main()':
007.cpp:35:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d %d %d %d %d", &n, &m, &s1, &s2, &t1, &t2);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
007.cpp:38:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &a, &b);
         ~~~~~^~~~~~~~~~~~~~~~~

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