uva 10801

Dij算法 需要对每个电梯进行预处理

#include <algorithm>
#include <cstring>
#include <cstdio>
#define INF 9999
#define N 110

using std::min;
using std::sort;
int dp[N][N];
int a[N];
int d[N];
int n,m;
char ch;
int time[7];
int v[N];
int front,rear;
void solve(int k,int nx)
{
    sort(a, a+nx);
    for(int i=0; i<nx; ++i)
    {
        for(int j=i+1; j<nx; ++j)
        {
            int c=a[i],d=a[j];
            int cc=(d-c)*time[k];
            if(dp[c][d]>cc)
                dp[d][c]=dp[c][d]=cc;
        }
    }
}
int main()
{
    while(scanf("%d %d",&n,&m)==2)
    {
        for(int i=0; i<n; ++i)
            scanf("%d",&time[i]);
        for(int i=0; i<N; ++i) d[i]=INF;
        for(int i=0; i<N; ++i)
            for(int j=0; j<N; ++j)
                dp[i][j]=INF;
        for(int i=0; i<n; ++i)
        {
            int ans=0;
            while(scanf("%d%c",&front,&ch)==2)
            {
                a[ans++]=front;
                if(ch=='\n') break;
            }
            solve(i,ans);
        }
        memset(v, 0, sizeof(v));
        d[0]=0;
        for(int i=0; i<=100; ++i)
        {
            int x,mm=INF;
            for(int y=0; y<=100; ++y)
                if(!v[y] && d[y]<mm) mm=d[x=y];
            v[x]=1;
            for(int y=0; y<=100; ++y)
                d[y]=min(d[y],d[x]+dp[x][y]+60);
        }
        if(d[m]>=INF) puts("IMPOSSIBLE");
        else if(!m) printf("0\n");
        else
            printf("%d\n",d[m]-60);
    }
    return 0;
}