;const int maxn = 110 ;const int inf = 0x7fffffff ;int dp[maxn][maxn*10] ;int c[maxn][maxn] ;int v[maxn][maxn] ;int len[maxn] ;int n ;int main(){ // freopen(“in.txt” ,”r” , stdin) ;int t ;scanf(“%d” , &t) ;while(t–){scanf(“%d” , &n) ;int ma = 0 ;for(int i = 1;i <= n;i++){scanf(“%d” , &len[i]) ;for(int j = 1;j <= len[i] ; j++){scanf(“%d%d” , &c[i][j] , &v[i][j]) ;ma = max(c[i][j] , ma) ;}}memset(dp , 0 , sizeof(dp)) ;for(int i = 1;i <= n;i++){for(int j = 0 ;j <= ma ;j++){if(dp[i-1][j] == inf){dp[i][j] = inf;continue ;}int mi = inf ;for(int k = 1;k <= len[i];k++)if(c[i][k] >= j)mi = min(v[i][k] , mi) ;if(mi == inf){dp[i][j] = inf ;continue ;}dp[i][j] = dp[i-1][j] + mi ;}}double ans = 0 ;for(int i = 1;i <= ma;i++)ans = max(ans , (double)i/(double)dp[n][i]) ;printf(“%.3lf\n” , ans) ;}return 0 ;}
，每一个成功者都有一个开始。勇于开始，才能找到成功的路。
