Invert

#include <iostream>

using namespace std;
#define N (1<<17)
int t[2*N];

long laske(int a, int b){
  a+=N, b+=N;
  int V=0;
  while(a<=b){
    if(a%2==1) V+=t[a++];
    if(b%2==0) V+=t[b--];
    a/=2, b/=2;
  }
  return V;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long q, V=0;
  cin >> q;
  for(int i=0; i<q; ++i){
    int c, a; cin >> c;
    if(c==3){
      V=0;
      continue;
    }else if(c==4){
      cout << V << "\n";
      continue;
    }
    cin >> a;
    if(c==1){
      V+= laske(a+1, N-1);
      int k=N+a;
      ++t[k];
      for(k/=2; k>=1; k/=2){
        t[k]=t[2*k]+t[2*k+1];
      }
    }
    else if(c==2){
      V+= laske(0, a-1);
      int k=N+a;
      ++t[k];
      for(k/=2; k>=1; k/=2){
        t[k]=t[2*k]+t[2*k+1];
      }
    }
  }
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED