845D - Driving Test - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;
const int maxn=2e5+10;
int st[maxn],tt=0;
int main(){
	int n,k,op,curv,ans=0,cnt=0;
	scanf("%d",&n);
	while(n--){
		scanf("%d",&op);
		if(op==1){
			scanf("%d",&curv);
		}
		else if(op==2){
			ans+=cnt;
			cnt=0;
		}
		else if(op==3){
			scanf("%d",&st[++tt]);
		}
		else if(op==4) cnt=0;
		else if(op==5) tt=0;
		else cnt++;
		while(tt&&st[tt]<curv){
			ans++;
			tt--;
		}
	}
	printf("%d",ans);
}