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 (≤105), 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
题意是找到最大的天数E,使得那天骑行的距离小于天数即可
#include<cstdio>
#include<algorithm>
using namespace std;
int arr[100010];
bool cmp(int a, int b){
return a > b;
}
int main(){
int n;
scanf("%d", &n);
for(int i = 0;i < n;i++){
scanf("%d", &arr[i]);
}
sort(arr, arr + n, cmp);
int c = 0;
while(c < n && arr[c] > c + 1){
c++;
}
printf("%d", c);
return 0;
}