cf914D. Bash and a Tough Math Puzzle(线段树)

#include<bits/stdc++.h>
using namespace std;
const int MAXN = 3e6 + 10, INF = 1e9 + 10;
inline int read() {
    char c = getchar(); int x = 0, f = 1;
    while(c < '0' || c > '9') {if(c == '-')f =- 1; c = getchar();}
    while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
    return x * f;
}
int N, M, a[MAXN];
#define ls k << 1
#define rs k << 1 | 1 
struct Node {
    int l, r, g;
}T[MAXN];
int gcd(int a, int b) {
    return (b == 0 ? a : gcd(b, a % b));
}
void update(int k) {
    T[k].g = gcd(T[ls].g, T[rs].g);
}
void Build(int k, int ll, int rr) {
    T[k] = (Node) {ll, rr};
    if(ll == rr) {T[k].g = a[ll]; return ;}
    int mid = T[k].l + T[k].r >> 1;
    Build(ls, ll, mid); Build(rs, mid + 1, rr);
    update(k);
}
void PointChange(int k, int pos, int val) {
    if(T[k].l == T[k].r) {T[k].g = val; return ;}
    int mid = T[k].l + T[k].r >> 1;
    if(pos <= mid) PointChange(ls, pos, val); 
    else PointChange(rs, pos, val);
    update(k);
}
int sum = 0;
void IntervalTims(int k, int ll, int rr, int val) {
    if(sum > 1) return ;
    if(T[k].l == T[k].r) sum++;
    int mid = T[k].l + T[k].r >> 1;
    if(ll <= mid && (T[ls].g % val)) IntervalTims(ls, ll, rr, val);
    if(rr  > mid && (T[rs].g % val)) IntervalTims(rs, ll, rr, val);
}
main() {
    N = read();
    for(int i = 1; i <= N; i++) a[i] = read();
    Build(1, 1, N);
    M = read();
    while(M--) {
        int opt = read();
        if(opt == 1) {
            int l = read(), r = read(), x = read();
            sum = 0; IntervalTims(1, l, r, x);
            puts(sum > 1 ? "NO" : "YES");
        } else {
            int pos = read(), x = read();
            PointChange(1, pos, x);
        }
    }
}
/*
*/