SDUT 最短路径（二维SPFA）

http://acm.sdut.edu.cn/sdutoj/problem.php?action=showproblem&problemid=2622

#include<stdio.h>
#include<string.h>
#include<queue>
#include<vector>
using namespace std;
const long long INF = 1LL << 40;
struct node
{
    int v,w;
};
vector<struct node>map[110];
int inque[110];
long long dis[110][12];
int s,t,x,n,m;

void spfa()
{
    queue<int>que;
    for(int i = 0; i < n; i++)
        for(int k = 0; k <= x; k++)
            dis[i][k] = INF;
    dis[s][0] = 0;
    memset(inque,0,sizeof(inque));

    que.push(s);
    inque[s] = 1;

    while(!que.empty())
    {
        int u = que.front();
        inque[u] = 0;
        que.pop();
        for(int i = 0; i < map[u].size(); i++)
        {
            int v = map[u][i].v;
            for(int k = 0; k < x; k++)
            {
                if(dis[u][k] < INF && dis[v][(k+1)%x] > dis[u][k]+map[u][i].w)
                {
                    dis[v][(k+1)%x] = dis[u][k]+map[u][i].w;
                    if(!inque[v])
                    {
                        que.push(v);
                        inque[v] = 1;
                    }
                }
            }
        }
    }
}
int main()
{
    int test;
    scanf("%d",&test);
    while(test--)
    {
        scanf("%d %d",&n,&m);
        for(int i = 0; i < n; i++)
            map[i].clear();
        int u,v,w;
        for(int i = 1; i <= m; i++)
        {
            scanf("%d %d %d",&u,&v,&w);
            map[u].push_back((struct node){v,w});
        }
        scanf("%d %d %d",&s,&t,&x);
        spfa();
        if(dis[t][0] >= INF)
            printf("No Answer!
");
        else printf("%lld
",dis[t][0]);
    }
    return 0;
}