Cod sursa(job #159891)

Utilizator tvladTataranu Vlad tvlad Data 14 martie 2008 14:58:37
Problema Range minimum query Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 0.82 kb
#include <cstdio>
#include <cmath>

const int N = 100000;
const int lgN = 17;

int n,m;
int a[N];
int d[lgN][N];

inline int min ( int a, int b ) {
	if (a == 0) return b;
	if (b == 0) return a;
	return (a < b) ? a : b;
}

int main() {
	freopen("rmq.in","rt",stdin);
	freopen("rmq.out","wt",stdout);
	scanf("%d %d",&n,&m);
	for (int i = 0; i < n; ++i) scanf("%d",&a[i]);

	for (int i = 0; i < n; ++i) d[0][i] = a[i];
	for (int j = 1; (1 << j) <= n; ++j) {
		for (int i = 0; i+(1<<j)-1 < n; ++i) {
			d[j][i] = min(d[j-1][i],d[j-1][i+(1<<(j-1))]);
		}
	}

	int p,q,ans;
	for (int i = 0; i < m; ++i) {
		scanf("%d %d",&p,&q);
		--p; --q;
		if (p == q) {
			ans = a[p];
		} else {
			int k = (int)(log((double)q-p+1)/log((double)2));
			ans = min(d[k][p],d[k][q-(1<<k)+1]);
		}
		printf("%d\n",ans);
	}
}