AcWing 1273. 天才的记忆 （RMQ范围最值查询）

 

 

#include <iostream>
#include <cstring>
#include <cmath>
using namespace std;
const int N = 200010, M = 18;

int n,m;
int w[N],f[N][M];

void init() {
    for(int j = 0; j < M; j++) {
        for(int i = 1; i + (1 << j) <= N; i++) {
            if(!j) f[i][j] = w[i];
            else f[i][j] = max(f[i][j-1],f[i+(1<<(j-1))][j-1]);
        }
    }
}

int query(int l, int r) {
    int len = r - l + 1;
    int k = log(len) / log(2);
    return max(f[l][k],f[r-(1<<k)+1][k]);
}


int main() {
    scanf("%d",&n);
    for(int i = 1; i <= n; i++) {
        scanf("%d",&w[i]);
    }
    init();
    scanf("%d",&m);
    while(m -- ) {
        int l, r;
        scanf("%d%d",&l,&r);
        printf("%d
",query(l,r));
    }
    return 0;
}