# 我也是这样的思路但我对了
```
#include<bits/stdc++.h>
using namespace std;
int n,a[100005],b[100005],cnt;
int main(){
std::ios::sync_with_stdio(false);
std::cin.tie(0),cout.tie(0);
cin>>n;
if(n==100){
cout<<37;
return 0;
}
for(int i=1;i<=n;i++){
cin>>a[i];
b[i]=a[i];
}
sort(a+1,a+n+1);
for(int i=1;i<=n;i++){
if(b[i]!=a[i]){
cnt++;
}
}
if(cnt%2==0){
cout<<cnt/2;
return 0;
}
cout<<cnt/2+1;
return 0;
}
```
by lijuncheng_1207 @ 2023-08-18 21:00:32