poj 1161 最短路构图

题目链接：http://poj.org/problem?id=1161

#include <cstdio>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <cstring>
#include <queue>
#include <vector>#define maxn 400
#define INF  0x3f3f3f
#define min(a,b) (a>b?b:a)
using namespace std;int first[maxn][maxn]; 
int d[maxn][maxn];
vector<int> G[maxn];
int N,M,L;
int mem[35];void floyd(){for(int k=1;k<=M;k++)for(int i=1;i<=M;i++){for(int j=1;j<=M;j++){d[i][j] = min(d[i][j],d[i][k]+d[k][j]);}}      
}
int main()
{scanf("%d%d%d",&M,&N,&L);    for(int i=1;i<=L;i++){scanf("%d",&mem[i]);}memset(first,0,sizeof(first));memset(d,0x3f,sizeof(d)); for(int i=1;i<=M;i++){int k,a,b,c;scanf("%d%d",&k,&a);G[a].push_back(i);k--;   b = a;while(k--){scanf("%d",&c);G[c].push_back(i);if(!first[b][c])first[b][c] = first[c][b] = i;else{d[first[b][c]][i] = d[i][first[c][b]] = 1;  //复制粘贴的代码太可怕了 
             }b = c;}if(!first[a][b])first[a][b] = first[b][a] = i;else{d[first[a][b]][i] = d[i][first[a][b]] = 1;}}for(int i=1;i<=M;i++) d[i][i] = 0;floyd();int ans = INF;for(int i=1;i<=M;i++){int sum = 0;for(int j=1;j<=L;j++){int u = mem[j];  int mincross = INF;for(int k=0;k<G[u].size();k++){int v = G[u][k];mincross = min(mincross,d[v][i]);}sum += mincross;    }ans = min(ans,sum);    }printf("%d\n",ans);
}

反正是WA的很伤心啊！