hiho 1068 重新整理的 Sparse-Table(RMQ)模板

http://hihocoder.com/problemset/problem/1067
代码:

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <string>
#include <queue>
#include <stack>
#include <vector>
#include <map>
#include <set>
#include <functional>
#include <cctype>
#include <time.h>

using namespace std;

struct Sparse_Table {
    static const int MAXN = (int)1e6+55;
    static const int MAXM = 21;

    int ST[MAXM][MAXN];
    int bit[MAXN];
    int n;

    void init() { //初始化bit数组，放在程序开始的时候，只需做一次
        bit[0] = bit[1] = bit[1] = 0;
        for (int i = 1; (i<<1)<MAXN; i++)
            bit[i<<1] = bit[i<<1|1] = bit[i]+1;
    }

    void initTable(int a[], int n) {
        this->n = n;
        for (int i = 0; i < n; i++)
            ST[0][i] = a[i];
        int hight = bit[n];
        for (int i = 0; i < hight; i++)
            for (int j = 0; j+(1<<i) < n; j++)
                    ST[i+1][j] = min(ST[i][j], ST[i][j+(1<<i)]);
    }

    inline int Query(int l, int r) {
        if (l==r) return ST[0][l];
        int h = bit[r-l+1];
        return min(ST[h][l], ST[h][r-(1<<h)+1]);
    }

    void output() {
        int h = bit[n];
        for (int i = 0; i <= h; i++) {
            for (int j = 0; j < n; j++)
                printf("%d ", ST[i][j]);
            puts("");
        }
    }
};

const int INF = 1<<30;
const int MAXN = 1e6+55;

Sparse_Table solver;
int a[MAXN];
int n, Q;

int main() {
    #ifdef Phantom01
        freopen("1068.txt", "r", stdin);
    #endif //Phantom01

    solver.init();

    while (scanf("%d", &n)!=EOF) {
        for (int i = 0; i < n; i++) scanf("%d", &a[i]);

        solver.initTable(a, n);
        scanf("%d", &Q);
        for (int i = 0; i < Q; i++) {
            int l, r;
            scanf("%d%d", &l, &r);
            printf("%d
", solver.Query(l-1, r-1));
        }
    }

    return 0;
}