Cod sursa(job #779319)

Utilizator visanrVisan Radu visanr Data 17 august 2012 14:53:44
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.11 kb
#include <cstdio>
#include <cstdlib>
#include <cmath>
using namespace std;

#define nmax 100010

int N, M, RMQ[nmax][20], v[nmax], X, Y;


void RangeMinimumQuery()
{
     int i, j;
     for(i = 0; i < N; i++) RMQ[i][0] = i;
     for(j = 1; (1 << j) <= N; j++)
     {
           for(i = 0; i + (1 << j) - 1 < N; i++)
           {
                 if(v[RMQ[i][j - 1]] < v[RMQ[i + (1 << (j - 1))][j - 1]])
                               RMQ[i][j] = RMQ[i][j - 1];
                 else
                     RMQ[i][j] = RMQ[i + (1 << (j - 1))][j - 1];
           }
     }
}

int main()
{
    freopen("rmq.in", "r", stdin);
    freopen("rmq.out", "w", stdout);
    int i;
    scanf("%i %i", &N, &M);
    for(i = 0; i < N; i++) scanf("%i", &v[i]);
    RangeMinimumQuery();
    for(; M; M --)
    {
          scanf("%i %i", &X, &Y);
          X --; Y --;
          int K = (int) log2(Y - X + 1);
          if(v[ RMQ[X][K] ] <= v[ RMQ[Y - (1 << K) + 1][K] ]) printf("%i\n", v[ RMQ[X][K] ]);
          else printf("%i\n", v[ RMQ[Y - (1 << K) + 1][K] ]);
    }
    scanf("%i", &i);
    return 0;
}