2020CCPC- 网络选拔赛 1010 Reports

题目链接
一道签到题
0和1必须间隔出现
AC代码：

#include<iostream>
#include<cstdio>
using namespace std;
const int maxn = 105;
int T,n,a,b;
int main()
{
    
    
    cin>>T;
    while(T--){
    
    
        cin>>n;
        int f = 1;
        n--;
        cin>>a;
        while(n--){
    
    
            cin>>b;
            if (a == b) f = 0;
            a = b;
        }
        if (f) cout<<"YES"<<endl;
        else cout<<"NO"<<endl;
    }
    return 0;
}