题解：P14245 [CCPC 2024 Shandong I] 左移

//头文件省略

int t;
int main(){
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
	cin>>t;
	for(int n=1;n<=t;n++){
		string s;
		cin>>s;
		int len=s.size();
		int m=s[len-1];
		if(s[0]==m || len==1){
			cout<<0<<endl;
			continue;
		}else{
			bool cnt=false;
			for(int i=0;i<len;i++){
				if(s[i]==s[i+1]){
					cnt=true;
					cout<<i+1<<endl;
					break;
				}
			}
			if(!cnt) cout<<-1<<endl;
		}
	}
	return 0;
}