全wa 求助

#include<bits/stdc++.h>
using namespace std;
const int N = 200005;
int cnt = 0, m;
char op;
long long n, lg[N], a[N], st[N][21], t=0, d;
void change(int x){
	st[x][0] = a[x];
    for(int j = 1;(1 << j) <= cnt; j++){
        int i = cnt-(1<<j)+1;
        if(i < 1) break;
        st[i][j] = max(st[i][j-1], st[i+(1<<(j-1))][j-1]);
    }
}
inline long long query(int l,int r){
    int len = r-l+1;
    int k = lg[len]; 
	return max(st[l][k], st[r+(1<<k)-1][k]);
}
signed main(){
	scanf("%d%lld", &m, &d);
	lg[0] = -1;
	for(int i = 1;i <= m; i++) lg[i] = lg[i >> 1]+1;
	for(int i = 1;i <= m; i++){
		cin >> op;
        if(op == 'A'){
			scanf("%lld", &n); 
			a[++cnt] = (n+t)%d; 
            change(cnt);
        }
		else if(op == 'Q'){
			int L;
			scanf("%d", &L);
            long long ans = query(cnt-L+1, cnt);
			printf("%lld\n", ans);
            t = ans;
		}
	}
	return 0;
}