LightOJ - 1019 Brush (V)(floyd)

题目大意：求第一点和最后一点的最短距离

解题思路：100的量，floyd搞起

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 110;
const int INF = 0x3f3f3f3f;
int dis[N][N];
int n, m, cas = 1;
void init() {
    scanf("%d%d", &n, &m);
    memset(dis, 0x3f, sizeof(dis));

    for (int i = 1; i <= n; i++)
        dis[i][i] = 0;
    int u, v, d;
    for (int i = 0; i < m; i++) {
        scanf("%d%d%d", &u, &v, &d);
        dis[u][v] = dis[v][u] = min(dis[u][v], d);
    }
}

void solve() {
    for (int k = 1; k <= n; k++)
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= n; j++)
                if (dis[i][k] != INF && dis[k][j] != INF && dis[i][j] > dis[i][k] + dis[k][j]) 
                    dis[i][j] = dis[i][k] + dis[k][j];

    if (dis[1][n] == INF) printf("Case %d: Impossible\n", cas++);
    else printf("Case %d: %d\n", cas++, dis[1][n]);

}

int main() {
    int test;
    scanf("%d", &test);
    while (test--) {
        init();
        solve();
    }
    return 0;
}