1117 Eddington Number (25分)

1117 Eddington Number (25分)
British astronomer Eddington liked to ride a bike. It is said that in order to show off his skill, he has even defined an “Eddington number”, E – that is, the maximum integer E such that it is for E days that one rides more than E miles. Eddington’s own E was 87.

Now given everyday’s distances that one rides for N days, you are supposed to find the corresponding E (≤N).

Input Specification:
Each input file contains one test case. For each case, the first line gives a positive integer N (≤10
​5
​​ ), the days of continuous riding. Then N non-negative integers are given in the next line, being the riding distances of everyday.

Output Specification:
For each case, print in a line the Eddington number for these N days.

Sample Input:

10
6 7 6 9 3 10 8 2 7 8

Sample Output:

6

#include<iostream>
#include<algorithm>
#define maxn 100005
using namespace std;

int i,n;
int dist[maxn];
int main(){
   
	std::ios::sync_with_stdio(false);
	std::cin.tie(0);
	cin>>n;
	for(i=1;i<=n;i++) cin>>dist[i];
	sort(dist+1,dist+n+1,greater<int>());
	for(i=1;i<=n;i++)
	{
   
		if(dist[i]<=i) break;
	}
	cout<<--i<<endl;
	
}