【hihoCoder第十六周】RMQ-ST算法

RMQ的大裸题。没什么意思。开始数组开小了，RE了一次。下面放代码。

#include <bits/stdc++.h>
using namespace std;

vector<int> A;
int dp[1000005][20];

void RMQ_init () {
    int n = A.size();
    for (int i = 0; i < n; ++ i) {
        dp[i][0] = A[i];
    }
    for (int j = 1; (1 << j) <= n; ++ j) {
        for (int i = 0; i + (1 << j) - 1 < n; ++ i) {
            dp[i][j] = min(dp[i][j - 1], dp[i + (1 << (j - 1))][j - 1]);
        }
    }
}

int RMQ (int L, int R) {
    int k = 0;
    while ((1 << (k + 1)) <= R - L + 1) ++ k;
    return min(dp[L][k], dp[R - (1 << k) + 1][k]);
}

int main () {
    int n;
    while (~scanf ("%d", &n)) {
        int x, op_n;
        for (int i = 0 ; i < n; ++ i) {
            scanf ("%d", &x);
            A.push_back(x);
        }
        /*
        for (int i = 0; i < A.size() - 1; ++ i) {
            cout << A[i] << endl;
        }
        */
        RMQ_init ();
        int a, b;
        scanf ("%d", &op_n);
        for (int i = 0; i < op_n; ++ i) {
            scanf ("%d%d", &a, &b);
            printf ("%d
", RMQ(a - 1, b - 1));
        }
    }
    return 0;
}