Educational Codeforces Round 130 (Rated for Div. 2) C – awoo's Favorite Problem

看题解发现是我自己读错题了……
一开始以为可以这样："abc"->"bac"->"cab"->"cba"
然后就卡了一个多小时，wa无数发

#include<bits/stdc++.h>
using namespace std;

typedef pair<int,int> pii;
typedef long long LL;

const int INF = 0X3f3f3f3f,N = 2e6+10;

int main(){
	int test;
	cin>>test;

	while(test--)
	{
		bool flag=true;
		string s1,s2;
		int n;
		cin>>n>>s1>>s2;
		for(auto c:{'a','b','c'})
			if(count(s1.begin(),s1.end(),c)!=count(s2.begin(),s2.end(),c)){
				flag=false;
				break;
			}
		vector<char> a(n+1),b(n+1);
		for(int i=1;i<=n;i++){
			if(s1[i-1]!='b')
				a.push_back(s1[i-1]);
			if(s2[i-1]!='b')
				b.push_back(s2[i-1]);
		}
		if(a!=b) flag=false;
		else{
			int x1=0,y1=0,z1=0,x2=0,y2=0,z2=0;
			for(int i=0;i<n;i++){
				if(s1[i]=='a') x1++;
				else if(s1[i]=='b') y1++;
				else z1++;
				if(s2[i]=='a') x2++;
				else if(s2[i]=='b') y2++;
				else z2++;
				if(x1<x2 || z1>z2) flag=false;
			}
		}
		if(flag) cout<<"YES"<<endl;
		else cout<<"NO"<<endl;
	}
	
	return 0;
}