贪心做，二分判断第一个可以交换的位置，怎么挂了？

二分只分了一半，因为过不了大样例

而且小数据没挂，大数据挂了

我调了快7个小时了，想紫砂

#include<bits/stdc++.h>
using namespace std;
const int N=2e5+10;
int T,p=0;
int n,ans;
char s1[N],s2[N],t1[N],t2[N];
int pos_s1[N],pos_s2[N],pos_s3[N],pos_s4[N],pos_t1[N],pos_t2[N];
int cnt1,cnt2,cnt3,cnt4,cnt5,cnt6;
int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	freopen("edit2.in","r",stdin);
	cin>>T;
	while(T--){
		ans=cnt1=cnt2=cnt3=cnt4=cnt5=cnt6=0;
		cin>>n;
		cin>>s1+1>>s2+1>>t1+1>>t2+1;
		for(int i=1;i<=n;i++){
			if(s1[i]=='0') pos_s1[++cnt1]=i;
			if(s1[i]=='1') pos_s2[++cnt2]=i;
			if(s2[i]=='0') pos_s3[++cnt3]=i;
			if(s2[i]=='1') pos_s4[++cnt4]=i;
			if(t1[i]=='0') pos_t1[++cnt5]=i;
			if(t2[i]=='0') pos_t2[++cnt6]=i;
		}
		pos_t1[++cnt5]=pos_t2[++cnt6]=n+1; 
		for(int i=1;i<=n;i++){
			//cout<<s1+1<<endl;
			//cout<<s2+1<<endl;
			//cout<<endl;
			if(s1[i]==s2[i]) continue;
			else if(s1[i]!=s2[i]){
				if(t1[i]=='1'){
					int k1=upper_bound(pos_s1+1,pos_s1+cnt1+1,i)-pos_s1;
					int k2=upper_bound(pos_s2+1,pos_s2+cnt2+1,i)-pos_s2;
					int r1=pos_s1[k1];
					int r2=pos_s2[k2];
					int c1=upper_bound(pos_t1+1,pos_t1+cnt5+1,i)-pos_t1;
					c1=pos_t1[c1];
					if(s1[i]=='1'){
						if(k1<=cnt1&&r1<c1) swap(s1[i],s1[r1]);
					}
					else if(s1[i]=='0'){
						if(k2<=cnt2&&r2<c1) swap(s1[i],s1[r2]);
					}			
				}
				if(t2[i]=='1'&&s1[i]!=s2[i]){
					for(int j=i+1;j<=n;j++){
						if(t2[j]=='0') break;
						if(s2[j]==s1[i]){
							swap(s2[j],s2[i]);
							break;
						}
					}
				}
			}
			
		}
		for(int i=1;i<=n;i++){
			if(s1[i]==s2[i]) ans++;
		}
		cout<<ans<<endl;
	}

	return 0;
}