Acwing——1275.最大数

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#define ls (u << 1)
#define rs (u << 1 | 1)

using namespace std;

const int N = 200010;

int mod, n, m, last;

struct Node {
    int l, r;
    int v;
}tr[N * 4];

void pushup(int u) {
    tr[u].v = max(tr[ls].v, tr[rs].v);
}

void build(int u, int l, int r) {
    tr[u].l = l, tr[u].r = r;
    if(l == r) return;
    int mid = (l + r) >> 1;
    build(ls, l, mid), build(rs, mid + 1, r);
}

void modify(int u, int x, int v) {
    if(tr[u].l == x && tr[u].r == x) tr[u].v = v;
    else {
        int mid = (tr[u].l + tr[u].r) >> 1;
        if(x <= mid) modify(ls, x, v);
        else modify(rs, x, v);
        pushup(u);
    }
}

int query(int u, int l, int r) {
    if(l <= tr[u].l && tr[u].r <= r) return tr[u].v;
    int mid = (tr[u].l + tr[u].r) >> 1;
    int v = 0;
    if(l <= mid) v = query(ls, l, r);
    if(r > mid) v = max(v, query(r, l, r));
    return v;
}

int main() {
    
    scanf("%d%d", &m, &mod);
    
    build(1, 1, m);
    
    char op[2];
    int x;
    while (m -- ) {
        scanf("%s%d", op, &x);
        if(*op == 'A') {
            n ++;
            x = (x + (long long)last) % mod;
            modify(1, n, x);
        }
        else {
            last = query(1, n - x + 1, n);
            printf("%d\n", last);
        }
    }
    
    return 0;
}

不知道为什么MLE了，求助