题解

#include<bits/stdc++.h>
#define ll long long                                                                 //防抄袭标记
using namespace std;
string a;
int r = -1;
char b[105];
int main(){
	cin>>a;
	for(int i = 0;i<a.size();i++){
		if(a[i]!='('&&a[i]!=')') continue;
		if(a[i]=='('){
			r++;
			b[r] = '(';
		} 
		if(a[i] == ')'){
			if(b[r] == '('){
				r--;
			}
			else{
				cout<<"NO"<<endl;
				return 0;
			}
		}
	}
	if(r == -1) cout<<"YES";
	else cout<<"NO";
	return 0;
}