【HDOJ】1385 Minimum Transport Cost

Floyd。注意字典序!!!

#include <stdio.h>
#include <string.h>

#define MAXNUM 55
#define INF 0x1fffffff

int cost[MAXNUM][MAXNUM];
int path[MAXNUM][MAXNUM];
int taxes[MAXNUM];
int que[MAXNUM];
int n;

void floyd(int n) {
    int i, j, k, tmp;

    for (i=1; i<=n; ++i)
        for (j=1; j<=n; ++j)
            path[i][j] = j;

    for (k=1; k<=n; ++k) {
        for (i=1; i<=n; ++i) {
            for (j=1; j<=n; ++j) {
                tmp = cost[i][k]+cost[k][j]+taxes[k];
                if (cost[i][j] > tmp) {
                    cost[i][j] = tmp;
                    path[i][j] = path[i][k];
                } else if (cost[i][j] == tmp) {
                    if (path[i][j] > path[i][k])
                        path[i][j] = path[i][k];
                }
            }
        }
    }
}

void output(int a, int b) {
    int front, rear;
    int x = a;
    front = rear = 0;

    //que[rear++] = a;
    while (path[x][b] != b) {
        que[rear++] = path[x][b];
        x = path[x][b];
    }
    if (a != b)
        que[rear++] = b;

    printf("From %d to %d :
", a, b);
    printf("Path: %d", a);
    while (front < rear)
        printf("-->%d", que[front++]);
    printf("
Total cost : %d

", cost[a][b]);
}

int main() {
    int a, b;
    int i, j;

    while (scanf("%d", &n)!=EOF && n) {
        for (i=1; i<=n; ++i)
            for (j=1; j<=n; ++j) {
                scanf("%d", &cost[i][j]);
                if (cost[i][j] < 0)
                    cost[i][j] = INF;
            }
        for (i=1; i<=n; ++i)
            scanf("%d", &taxes[i]);
        floyd(n);
        while (1) {
            scanf("%d %d", &a, &b);
            if (a==-1 && b==-1)
                break;
            output(a, b);
        }
    }

    return 0;
}