Cod sursa(job #2624158)

Utilizator grecuGrecu Cristian grecu Data 4 iunie 2020 16:01:54
Problema Range minimum query Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.37 kb
#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;

int N,M;
int rmqlen;

void build(int v[], int rmq[], int l = 0, int h = N - 1, int pos = 0){
    if(l == h){
        rmq[pos] = v[l];
    }
    else{
        int mid = (l + h)/2;
        build(v, rmq, l, mid, 2*pos + 1);
        build(v, rmq, mid + 1, h, 2*pos + 2);
        rmq[pos] = min(rmq[2*pos+1], rmq[2*pos+2]);
    }
}

int RMQ(int rmq[], int ql, int qh, int l = 0, int h = N - 1, int pos = 0){
    if(ql <= l && qh >= h)
        return rmq[pos];    // total overlap;
    if(ql > h || qh < l)
        return 100001;    // no overleap;
    int mid = (l + h)/2;
    return min(RMQ(rmq, ql, qh, l, mid, 2*pos+1), RMQ(rmq, ql, qh, mid+1, h, 2*pos + 2));

}

int main()
{
    ifstream f("rmq.in");
    ofstream g("rmq.out");
    f >> N >> M;
    rmqlen = N - 1;
    rmqlen |= rmqlen >> 1;
    rmqlen |= rmqlen >> 2;
    rmqlen |= rmqlen >> 4;
    rmqlen |= rmqlen >> 8;
    rmqlen |= rmqlen >> 16;
    rmqlen = 2*rmqlen + 1;
    int v[N],rmq[rmqlen], i;
    for(i = 0; i < N; i++){
        f >> v[i];
        if (i < rmqlen)
            rmq[i] = 100001;
    }
    for(; i < rmqlen; i++)
        rmq[i] = 100001;
    build(v, rmq);
    int x, y;
    for (i = 0; i < M; i++){
        f >> x >> y;
        g << RMQ(rmq, x-1, y-1)<<"\n";
    }

    return 0;
}