Cod sursa(job #373257)

Utilizator TabaraTabara Mihai Tabara Data 13 decembrie 2009 05:05:55
Problema Range minimum query Scor 100
Compilator c Status done
Runda Arhiva educationala Marime 0.85 kb
#include <stdio.h>

#define in "rmq.in"
#define out "rmq.out"
#define NMAX 100005
#define MMAX 18

long dp[MMAX][NMAX];
long N, M;
long A[NMAX], lg[NMAX];

int main ( void )
{
	freopen ( in, "r", stdin );
	freopen ( out, "w", stdout );

	scanf ( "%ld%ld", &N, &M );

	int i, j; 
	long X, Y, k;

	for ( i = 0; i < N; scanf( "%ld", A+i++ ) );

	lg[1] = 0;
	for ( i = 2; i < N; ++i ) lg[i] = lg[(i>>1)]+1;

	for ( i = 0; i < N; ++i )
		dp[0][i] = i;

	for ( j = 1; (1<<j) <= N; ++j )
		for ( i = 0; i + (1<<j)-1 < N; ++i )
			if ( A[dp[j-1][i]] < A[dp[j-1][i+(1<<(j-1))]] )
				dp[j][i] = dp[j-1][i];
			else
				dp[j][i] = dp[j-1][i+(1<<(j-1))];

	for ( ; M; --M )
	{
		scanf ( "%ld%ld", &X, &Y );
		X--; Y--;
		k = lg[Y-X+1];
		if ( A[dp[k][X]] < A[dp[k][Y-(1<<k)+1]] )
			printf ( "%ld\n", A[dp[k][X]] );
		else
			printf ( "%ld\n", A[dp[k][Y-(1<<k)+1]] );
	}

	return 0;
}