```cpp
#include<bits/stdc++.h>
#define Ll long long
using namespace std;
const int N=1e5+5;
map<int,int>F;
int a[N],b[N];
int n,m,ans;
int main()
{
scanf("%d",&n);
for(int i=1;i<=n;i++)scanf("%d",&a[i]),b[i]=a[i],F[a[i]]=i;
sort(b+1,b+n+1);
for(int i=1;i<=n;i++)
if(a[i]!=b[i]){
ans++;
int x=F[b[i]];
F[a[i]]=x;
a[x]=a[i];
}
printf("%d",ans);
}
```
by wangzixiang666 @ 2018-06-08 19:41:29