Invert

#include <iostream>
using namespace std;
#define SZ (1<<18)
int q;

int sp[SZ];

void st(int a){a+=SZ/2;
  ++sp[a];
  for (a/=2; a; a/=2) ++sp[a];
}

int gt(int a, int b){a+=SZ/2;b+=SZ/2;
  int rv=0;
  while (a<b){
    if (a%2==1) rv+=sp[a++];
    if (b%2==0) rv+=sp[b--];
    a/=2; b/=2;
  }if (a==b) rv+=sp[a];
  return rv;
}

long long inv;

int main(){
  cin >> q;
  for (int i=0; i<q; ++i){
    int t;
    cin >> t;
    if (t==1){
      int a;
      cin >> a;
      st(a);
      inv+=gt(a+1, 101010);
    }else if (t==2){
      int a;
      cin >> a;
      st(a);
      inv+=gt(0, a-1);
    }else if (t==3){
      inv=0;
    }else if (t==4){
      cout << inv << "\n";
    }
  }
}

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