Submission #82363

#	Time	Username	Problem	Language	Result	Execution time	Memory
82363		FutymyClone	007 (CEOI14_007)	C++14	0 / 100	413 ms	87572 KiB

007

#include <bits/stdc++.h>

using namespace std;

const int N = 2e5 + 5;

int n, m, s, d, a, b, dist[2][N];
vector <int> g[N];
queue <int> q;

void bfs (int type){
    if (!type) memset(dist, 0x3f, sizeof(dist));
    dist[type][(type == 0) ? d : s] = 0;
    q.push((type == 0) ? d : s);
    while (!q.empty()) {
        int u = q.front(); q.pop();
        for (auto v: g[u]) {
            if (type == 0 && v == s) continue;
            if (dist[type][v] > dist[type][u] + 1) {
                dist[type][v] = dist[type][u] + 1;
                q.push(v);
            }
        }
    }
}

int main(){
    #ifdef Futymy
        freopen("SPY.inp", "r", stdin);
        freopen("SPY.out", "w", stdout);
    #endif // Futymy
    scanf("%d %d", &n, &m);
    scanf("%d %d %d %d", &s, &d, &a, &b);
    for (int i = 1; i <= m; i++) {
        int u, v;
        scanf("%d %d", &u, &v);
        g[u].push_back(v); g[v].push_back(u);
    }

    bfs(0); bfs(1);
    //for (int i = 1; i <= n; i++) cout << dist[0][i] << " ";
    //cout << "\n";
    int Min = min(dist[0][a], dist[0][b]);
    //cout << dist[0][a] << " " << dist[0][b] << "\n";
    if (Min > 1e9) printf("%d", dist[1][d]);
    else {
        if (dist[0][a] < 1e9 && dist[0][b] > 1e9) {
            if (dist[1][a] > dist[0][a]) printf("%d", -1);
            else printf("%d", min(dist[1][d], dist[0][a] - dist[1][a]));
        }
        else if (dist[0][a] > 1e9 && dist[0][b] < 1e9) {
            if (dist[1][b] > dist[0][b]) printf("%d", -1);
            else printf("%d", min(dist[1][d], dist[0][b] - dist[1][b]));
        }
        else {
            if (dist[1][b] > dist[0][b] || dist[1][a] > dist[0][a]) printf("%d", -1);
            else printf("%d", min(dist[0][a] - dist[1][a], dist[0][b] - dist[1][b]));
        }
    }
    return 0;
}

Compilation message (stderr)

007.cpp: In function 'int main()':
007.cpp:32:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~~
007.cpp:33:10: 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:36:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &u, &v);
         ~~~~~^~~~~~~~~~~~~~~~~

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