【luogu P3865 ST表】 模板

跟忠诚是一样滴，不过是把min改成max就AC了。模板题。

#include <cstdio> 
#include <algorithm>
using namespace std;
const int maxn = 1000000;
int st[maxn][21], a[maxn], ans[maxn];
int i, j, n, m, left, right;
int main()
{
    scanf("%d%d", &n, &m);
    for(i = 1; i <= n; i++)
    {
        scanf("%d", &a[i]);
        st[i][0] = a[i];
    }
    
    for(j = 1; (1<<j) <= n; j++)
        for(i = 1; i <= n - (1<<j) + 1; i++)
        st[i][j] = max(st[i][j-1] , st[i + (1<< (j-1) )][j-1]);
    
    for(i = 1; i <= m; i++)
    {
        scanf("%d%d", &left, &right);
        j = 0;
        while((1<<(j+1)) <= (right-left+1)) j++;
        ans[i] = max(st[left][j],st[right-(1<<j)+1][j]);
    }
    
    for(i = 1; i <= m; i++)
    printf("%d
",ans[i]);
    return 0;
}