python/TangDou/Topic/HDU1385.cpp

#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;

const int N = 1003;
int g[N][N], path[N][N]; // 邻接矩阵、路径
int n, x, y, w[N];       // 额外费用
void floyd() {
    for (int k = 1; k <= n; k++)
        for (int i = 1; i <= n; i++)
            if (g[i][k] != INF)
                for (int j = 1; j <= n; j++) {
                    if (g[i][j] > g[i][k] + g[k][j] + w[k]) {
                        g[i][j] = g[i][k] + g[k][j] + w[k];
                        path[i][j] = path[i][k];
                    }
                    if (g[i][j] == g[i][k] + g[k][j] + w[k]) {
                        if (path[i][j] > path[i][k]) // 字典序
                            path[i][j] = path[i][k];
                    }
                }
}
int main() {
    while (cin >> n && n) {
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n; j++) {
                path[i][j] = j; // 路径初始化,如果i->j有边，则记录path[i][j]=j,就是记录i->j的中间节点
                cin >> g[i][j];
                if (g[i][j] == -1) g[i][j] = INF;
            }
        }
        for (int i = 1; i <= n; i++) cin >> w[i];
        floyd();

        while (cin >> x >> y) {
            if (x == -1 && y == -1) break;
            printf("From %d to %d :\n", x, y);
            printf("Path: %d", x);
            int u = x, v = y;
            // 用循环打印路径
            while (x != y) {
                printf("-->%d", path[x][y]);
                x = path[x][y];
            }

            puts("");
            if (g[u][v] < INF)
                printf("Total cost : %d\n", g[u][v]);
            else
                puts("-1");
            puts("");
        }
    }
    return 0;
}