[HDOJ3631]Shortest Path

简单题，动态全源对短路~

#include <cstdio>
#include <cstring>

const int SIZE = 512;
const int INF = 0x7F7F7F7F;

bool mark[SIZE];
int dist[SIZE][SIZE];
int ans[SIZE][SIZE];

int main()
{
    int nn;
    int nm;
    int nq;

    int uu;
    int vv;
    int val;

    int opp;
    int cas = 0;

    while (scanf("%d %d %d",&nn,&nm,&nq) == 3)
    {
        if (nn == 0 && nm == 0 && nq == 0) break;

        if(cas > 0) printf("\n");

        memset(mark,false,sizeof(mark));
        memset(dist,0x7F,sizeof(dist));
        memset(ans,0x7F,sizeof(ans));

        for (int i = 0;i < nn;i++)
            dist[i][i] = ans[i][i] = 0;

        for (int i = 0;i < nm;i++)
        {
            scanf("%d %d %d",&uu,&vv,&val);
            if (dist[uu][vv] > val)
                dist[uu][vv] = val;
        }

        printf("Case %d:\n",++cas);

        for (int i = 0;i < nq;i++)
        {
            scanf("%d",&opp);
            if (opp == 0)
            {
                scanf("%d",&uu);
                if (mark[uu])
                {
                    printf("ERROR! At point %d\n",uu);
                    continue;
                }
                mark[uu] = true;

                for (int i = 0;i < nn;i++)
                    if (mark[i])
                    {
                        ans[i][uu] = dist[i][uu];
                        ans[uu][i] = dist[uu][i];
                    }

                for (int i = 0;i < nn;i++)
                {
                    if (!mark[i]) continue;

                    if (ans[i][uu] != INF)
                        for (int j = 0;j < nn;j++)
                            if (mark[j] && ans[j][i] != INF)
                                if (ans[j][uu] > ans[j][i] + ans[i][uu])
                                    ans[j][uu] = ans[j][i] + ans[i][uu];
                    if (ans[uu][i] != INF)
                        for (int j = 0;j < nn;j++)
                            if (mark[j] && ans[i][j] != INF)
                                if (ans[uu][j] > ans[uu][i] + ans[i][j])
                                    ans[uu][j] = ans[uu][i] + ans[i][j];
                }

                for (int i = 0;i < nn;i++)
                    if (ans[i][uu] != INF)
                        for (int j = 0;j < nn;j++)
                            if (ans[uu][j] != INF)
                                if (ans[i][j] > ans[i][uu] + ans[uu][j])
                                    ans[i][j] = ans[i][uu] + ans[uu][j];
            }
            else
            {
                scanf("%d %d",&uu,&vv);
                if (!mark[uu] || !mark[vv]) printf("ERROR! At path %d to %d\n",uu,vv);
                else if (ans[uu][vv] == INF) printf("No such path\n");
                else printf("%d\n",ans[uu][vv]);
            }
        }
    }
    return 0;
}