谨以此文纪念我失败的E题

https://oj.acmclub.cn/problem.php?cid=1164&pid=4
#include <bits/stdc++.h>
#define N 200100
#define M 100000
using namespace std;
int num[N];
int idx;
int Max = -1;
int dp[N + 1][21];
void RMQ(int n);
int Log2(int n)
{
    return log(n * 1.0) / log(2.0);
}
int main()
{
    int n, q;
    while(scanf("%d", &n) != EOF && n)
    {
        memset(num, 0, sizeof(num));
        scanf("%d", &q);
        Max = -1;
        for(int i = 0; i < n; i++)
        {
            scanf("%d", &idx);
            idx += M;
            num[idx]++;
            if(idx > Max)
                Max = idx;
        }
        RMQ(Max);
        while(q--)
        {
            int l, r;
            scanf("%d%d", &l, &r);
            l += M;
            r += M;
            int ch = Log2(l - r + 1);
            printf("%d\n", max(dp[l][ch], dp[r - (1 << ch) + 1][ch]));
        }
    }
    return 0;
}
void RMQ(int n)// 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
{
    for(int i = 0; i <= n; i++)
    {
        dp[i][0] = num[i];
    }
    for(int j = 1; j <= 18; j++)
    {
        for(int i = 1; i <= n; i++)
        {
            if(i + (1 << j) - 1 <= n)
                dp[i][j] = max(dp[i][j - 1], dp[i + (1 << (j - 1))][j - 1]);
            else
            break;
        }
    }

}

https://oj.acmclub.cn/problem.php?cid=1164&pid=