D Almost Sorted 题解
Code:

#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
ll a[3000005];
int main()
{
    int n;cin>>n;for(int i=1;i<=n;i++) cin>>a[i];
    int x = 0, y = n+1;
    for(int i=2;i<=n;i++)if(a[i]< a[i-1]) {x=i-1;break;}
    for(int i=n;i>=1;i--)if(a[i]< a[i-1]) {y=i;break;}
    
    swap(a[x],a[y]);
    
    for(int i=2;i<=n;i++) if(a[i]<a[i-1]) {cout<<"NO\n";return 0;}
    cout<<"YES\n";
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
ll a[3000005];
int main()
{
int n;cin>>n;for(int i=1;i<=n;i++) cin>>a[i];
int x = 0, y = n+1;
for(int i=2;i<=n;i++)if(a[i]< a[i-1]) {x=i-1;break;}
for(int i=n;i>=1;i--)if(a[i]< a[i-1]) {y=i;break;}

swap(a[x],a[y]);

for(int i=2;i<=n;i++) if(a[i]<a[i-1]) {cout<<"NO\n";return 0;}
cout<<"YES\n";
return 0;
}