GCD queries

#include <bits/stdc++.h>

#define _ ios_base::sync_with_stdio(0);cin.tie();
#define ll long long
#define vi vector<int>
#define pb push_back
#define pii pair<int, int>
#define vpii vector<pii>
#define N (2<<20)
#define C 1234234234
using namespace std;

int gcd(int a, int b) { return b == 0 ? a : gcd(b, a%b); }

int t[2*N];

void c(int x, int k) {
  x += N;
  t[x] = k;
  x /= 2;
  while(x > 0) {
    int l = t[2*x];
    int r = t[2*x+1];
    if(l==C)
      t[x] = r;
    else if(r==C)
      t[x] = l;
    else
      t[x] = gcd(l,r);
    x /= 2;
  }
}

int g(int a, int b) {
  a += N; b += N;
  int cv = C;
  while(a <= b) {
    //cout << a << "|" << b << endl;
    if(a%2 == 1) {
      if(cv==C) cv=t[a];
      else cv=gcd(cv,t[a]);
      a++;
    }
    if(b%2 == 0) {
      if(cv==C) cv=t[b];
      else cv=gcd(cv,t[b]);
      b--;
    }
    a /= 2; b /= 2;
  }
  //cout << "-----" << endl;
  return cv;
}

int main() { _
  int n, q;
  cin >> n >> q;
  for(int i=0;i<2*N;i++) t[i]=C;
  for(int i=0;i<n;i++) {
    int x; cin >> x;
    c(i, x);
  }
  //for(int i=1;i<2*N;i++) cout << t[i] << endl;
  for(int i=0;i<q;i++) {
    char t; cin >> t;
    int a,b;
    cin >> a >> b;
    if(t == 'q') {
      a--; b--;
      cout << g(a, b) << endl;
    } else {
      c(a-1, b);
    }
  }
  return 0;
} 

Test 1

Verdict: UNKNOWN

Test 2

Verdict: UNKNOWN

Test 3

Verdict: UNKNOWN

Test 4

Verdict: UNKNOWN

Test 5

Verdict: UNKNOWN

Test 6

Verdict: UNKNOWN

Test 7

Verdict: UNKNOWN

Test 8

Verdict: UNKNOWN

Test 9

Verdict: UNKNOWN

Test 10

Verdict: UNKNOWN

Test 11

Verdict: UNKNOWN

Test 12

Verdict: UNKNOWN

Test 13

Verdict: UNKNOWN

Test 14

Verdict: UNKNOWN

Test 15

Verdict: UNKNOWN

Test 16

Verdict: UNKNOWN

Test 17

Verdict: UNKNOWN

Test 18

Verdict: UNKNOWN

Test 19

Verdict: UNKNOWN

Test 20

Verdict: UNKNOWN

Test 21

Verdict: UNKNOWN

Test 22

Verdict: UNKNOWN

Test 23

Verdict: UNKNOWN

Test 24

Verdict: UNKNOWN

Test 25

Verdict: UNKNOWN

Test 26

Verdict: UNKNOWN

Test 27

Verdict: UNKNOWN

Test 28

Verdict: UNKNOWN

Test 29

Verdict: UNKNOWN

Test 30

Verdict: UNKNOWN

Test 31

Verdict: UNKNOWN

Test 32

Verdict: UNKNOWN

Test 33

Verdict: UNKNOWN