PAT-A1117

#include<stdio.h> int day[1000010]={0}, day1[1000010]={0}; int main(){ int i, n, max=0, temp, pre=1000005, sum=0, result=0; scanf("%d",&n); for(i=0;i<n;i++){ scanf("%d",&temp); day[temp]++; if(temp>max)max=temp; } //for(i=0;i<=max;i++)printf("%d:%d ",i,day[i]);printf("\n"); for(i=max;i>=0;i--){ day1[i]=sum; sum=sum+day[i]; } //for(i=0;i<=max;i++)printf("%d:%d ",i,day1[i]);printf("\n"); for(i=max;i>=0;i--){ if(day1[i]>=i){result=i;break;} } printf("%d",result); return 0; }