北大POJ题目练习

图论

Stockbroker Grapevine

#include <iostream>
#include <cstdio>
using namespace std;
int ans[101][101];
int wtime[101][101];
int main() {
    int n;
    while (scanf("%d", &n) != EOF && n != 0) {
        int t, d, m;
        memset(ans, -1, sizeof(ans));
        for (int i = 1; i <= n; i++) {
            ans[i][i] = 0;
            cin >> m;
            for (int j = 0; j < m; j++) {
                cin >> t >> d;
                ans[i][t] = d;
            }

        }
        for (int k = 1; k <= n; k ++) {
            for (int i = 1; i <= n; i++) {
                for (int j = 1; j <= n; j++) {
                    if (ans[i][k] == -1 || ans[k][j] == -1)
                        continue;
                    if (ans[i][j] == -1 || ans[i][k] + ans[k][j] < ans[i][j])
                        ans[i][j] = ans[i][k] + ans[k][j];
                }
            }
        }
        int min = 9999999;
        int time = 0;
        int idx = -1;
        bool flag;
        for (int i = 1; i <= n; i++) {
            flag = true;
            time = 0;
            for (int j = 1; j <= n; j++) {
                if (ans[i][j] == -1) {
                    flag = false;
                    break;
                }
                if (time < ans[i][j])
                    time = ans[i][j];
            }
            if (flag && time < min){
                min = time;
                idx = i;
            }
        }
        cout << idx << " " << min << endl;
    }
    return 0;
}