代码如下

#include<bits/stdc++.h>
using namespace std;
int n,t;
char s[100005],s1[100005];
int main(){
	//freopen(".in","r",stdin);
	//freopen(".out","w",stdout);
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	cin>>t;
	while(t--){
		cin>>n;
		int k=0;
		bool flag=0;
		for(int i=1;i<=n;i++){
			cin>>s[i];
		}
		if(flag==1){
			break;
		}
		for(int i=n;i>=1;i--){
			s1[++k]=s[i];
		}
		int ans=0;
		for(int i=1;i<=n;i++){
			if(((s[i]=='A'&&s1[i]=='T')||(s1[i]=='A'&&s[i]=='T'))||((s[i]=='C'&&s1[i]=='G')||(s1[i]=='C'&&s[i]=='G'))){
				ans+=i;
			}
		}
		cout<<ans<<"\n"; 
	}
	
	return 0;
}