Cod sursa(job #582975)

Utilizator UpL1nKPaunescu Sorin UpL1nK Data 16 aprilie 2011 21:07:34
Problema Range minimum query Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 0.94 kb
#include <cstdio>
#define Nmax 100001

using namespace std;

int a[Nmax];
int r[25][Nmax];
int n, m;
int x, y;
int log[Nmax];

inline int min(int, int);
void process();

int main() {

    freopen("rmq.in", "r", stdin);
    freopen("rmq.out", "w", stdout);

    scanf("%d %d", &n, &m);

    for(int i = 1; i <= n; i++)
        scanf("%d ", &a[i]);

    process();

    for (int i = 2; i <= n; i++) {
        log[i] = log[i / 2] + 1;
    }

    for (int i = 1; i <= m; i++) {
        scanf("%d %d", &x, &y);
        int l = log[y - x + 1];
        printf("%d\n", min(r[l][x], r[l][y - l]));
    }

    return 0;
}

inline int min(int a, int b) {
    return a < b ? a : b;
}

void process() {

    for (int i = 1; i <= n; i++)
        r[0][i] = a[i];

    for (int i = 1; (1 << i) < n; i++)
        for (int j = 1; j <= n - (1 << i) + 1; j++)
            r[i][j] = min(r[i-1][j], r[i-1][j + (1 << (i - 1))]);
}