详解请看https://blog.csdn.net/u013377068/article/details/79900343

#include<stdio.h>
#include<algorithm>
using namespace std;

const int INF = 100010;

void ST();

int RMQ(int i ,int j);

int dp[INF][20];



void ST()
{
	for(int i = 1 ; i <= n; i++)
	dp[i][0] = A[i];
	
	for(int j = 1; (1 << j) <= n; j++)
	{
		for(int i =1; i + (1 << j) -1 <= n; i++)
		{
			dp[i][j] = max(dp[i][j-1], dp[i + (1 << (j-1))][j-1]);
		}
	}
	
	
	
}

int RMQ(int i, int j)
{
	if(i > j)
	return 0; 
	int k = 0;
	
	while((1<<(k + 1)) <= j -i +1)k++;			// k 为log2(j - i + 1) 
	
	return max(dp[i][k], dp[j - (1 << k) + 1][k]);
	
}