UVA 821(p379)----Page Hopping

#include<iostream>#include<cstdio>#include<algorithm>using namespace std;const int maxx=2147483647/3;int g[155][155],ans,num;void init(){    for(int i=0;i<=100;i++)        for(int j=0;j<=100;j++)          g[i][j]=maxx;}double solve(){    num=0;ans=0;    for(int k=1;k<=100;k++)        for(int i=1;i<=100;i++)          for(int j=1;j<=100;j++)            g[i][j]=min(g[i][j],g[i][k]+g[k][j]);    for(int i=1;i<=100;i++)        for(int j=1;j<=100;j++)           if(g[i][j]!=maxx&&(i!=j))           {               ans+=g[i][j];               num++;           }    return (double)ans/(double)num;}int main(){    int cas=0,a,b,x,y;    while((scanf("%d%d",&a,&b)!=EOF)&&a&&b)    {        init();g[a][b]=1;cas++;        while(scanf("%d%d",&x,&y)&&x&&y) g[x][y]=1;        printf("Case %d: average length between pages = %.3lf clicks\n",cas,solve());    }    return 0;}

题目地址： https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=762