Submission #861265

#	Time	Username	Problem	Language	Result	Execution time	Memory
861265		Ahmed57	Cat (info1cup19_cat)	C++17	0 / 100	28 ms	436 KiB

cat

#include <bits/stdc++.h>

using namespace std;
int main(){
    int t;cin>>t;
    z:while(t--){
        int n;cin>>n;
        int arr[n+1],pos[n+1];
        for(int i = 1;i<=n;i++){
            cin>>arr[i];pos[arr[i]] = i;
        }
        int g = 0;
        for(int i = 1;i<=n/2;i++){
            if((arr[i]==i)^(arr[n-i+1]==n-i+1)){
                cout<<-1<<endl;
                goto z;
            }
            if(arr[i]!=i)g++;
        }
        int e = 0;
        for(int i = 1;i<=n;i++){
            int x = pos[i];
            if(arr[i]==i)continue;
            if(arr[n-i+1]==n-x+1&&arr[n-x+1]==n-i+1){
                e++;
            }
        }
        cout<<g-(e/4)<<" "<<0<<endl;
    }
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 10
• Subtask 3: 0 / 25
• Subtask 4: 0 / 15
• Subtask 5: 0 / 35