HDU_1385 Minimum Transport Cost( Dijkstra )

　　这题A 的很是纠结，从下午5点多开始做到现在，一直WA。。。其中滋味，别提了。。。请容我发泄两句。。。1385！WA你妹啊！！！

My Code:

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

const int N = 105;
const int inf = 10000000;

int dis[N][N];
int map[N][N];
int low[N];
int vis[N];
int pre[N];
int v[N];

int cmp(int src, int dest1, int dest2)
{
    int path1[N], path2[N];
    int len1 = 0, len2 = 0;

    memset(path1, 0, sizeof(path1));
    memset(path2, 0, sizeof(path2));

    while (src != dest1)
    {
        path1[len1++] = dest1;
        dest1 = pre[dest1];
    }


    while (src != dest2)
    {
        path2[len2++] = dest2;
        dest2 = pre[dest2];
    }


    while (path1[len1-1] == path2[len2-1])
    {
        len1--;
        len2--;
    }

    return path1[len1-1] < path2[len2-1];
}

void Dijkstra(int n, int v)
{
    int flag, i, j, min;
    for(i = 1; i <= n; i++)
    {
        low[i] = dis[v][i];
        vis[i] = 0;
        if(dis[v][i] >= inf)
            pre[i] = 0;
        else
            pre[i] = v;
    }
    vis[v] = 1;
    low[v] = 0;
    for(i = 2; i <= n; i++)
    {
        min = inf; flag = -1;
        for(j = 1; j <= n; j++)
        {
            if(min > low[j] && !vis[j])
            {
                min = low[j];
                flag = j;
            }
        }
        if(flag == -1)
            continue;
        vis[flag] = 1;
        for(j = 1; j <= n; j++)
        {
            if(!vis[j] && dis[flag][j] < inf)
            {
                int tmp = dis[flag][j] + low[flag];
                if(tmp < low[j])
                {
                    low[j] = tmp;
                    pre[j] = flag;
                }
                if(tmp == low[j])
                {
                    if(cmp(v, flag, pre[j]))
                    {
                        pre[j] = flag;
                    }
                }
                //printf("%d %d\n", j, pre[j]);
            }
        }
    }
}
void printroad(int a, int b)
{
    int sta[N];
    int len = 0;
    int root = b;
    while(root != a)
    {
        sta[len++] = root;
        root = pre[root];
    }
    printf("%d", a);
    while(len > 0)
    {
        printf("-->%d", sta[len-1]);
        len--;
    }
    printf("\n");
}
int main()
{
    //freopen("data.in", "r", stdin);

    int n, i, j, a, b;
    while(scanf("%d", &n), n)
    {
        for(i = 1; i <= n; i++)
            for(j = 1; j <= n; j++)
            {
                scanf("%d", &map[i][j]);
                if(map[i][j] == -1)
                    map[i][j] = inf;
            }
        for(i = 1; i <= n; i++)
            scanf("%d", &v[i]);

        while(~scanf("%d%d", &a, &b))
        {
            if(a == -1 && b == -1)
                break;
            
            for(i = 1; i <= n; i++)
                for(j = 1; j <= n; j++)
                {
                    if(j == a || j == b || i == j)
                        dis[i][j] = map[i][j];
                    else
                        dis[i][j] = map[i][j] + v[j];
                }
            
            Dijkstra(n, a);
            printf("From %d to %d :\n", a, b);
            printf("Path: ");
            printroad(a, b);
            printf("Total cost : %d\n\n", low[b]);
        }
    }
    return 0;
}