RMQ问题模板（ST算法）

#include<bits/stdc++.h>
using namespace std;
#define MAXN 1000+10
int dp[MAXN][MAXN], a[MAXN]; 

void InitRMQ(int l, int r, int n){
    int k = floor((double)log(r-l+1)/log(2));
    for (int i = 1; i <= n; ++i) dp[i][0] = a[i];
    for (int j = 1; j <= k; ++j)
        for (int i = 1; i+(1<<j-1) <= r; ++i)
            dp[i][j] = max(dp[i][j-1], dp[i+(1<<j-1)][j-1]); 
}

int getmax(int l, int r){
    int k = floor((double)log(r-l+1)/log(2));
    return max(dp[l][k], dp[r-(1<<k)][k]);
}

int main()
{
    int n, q;
    cin>>n>>q;
    for (int i = 1; i <= n; ++i) cin>>a[i];
    InitRMQ(1, n, n);
    int l, r;
    while(q--){
        cin>>l>>r;
        cout<<getmax(l, r)<<endl;
    }

    return 0;
}