Cod sursa(job #1868604)

Utilizator Horia14Horia Banciu Horia14 Data 5 februarie 2017 00:49:19
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.68 kb
#include<cstdio>
#include<cctype>
#define BUF_SIZE 1<<17
#define NMAX 100001
#define MAX_VALUE 0x7fffffff
using namespace std;

int v[NMAX], segTree[4*NMAX], n, a, b;
char buf[BUF_SIZE];
int pos = BUF_SIZE;

inline int minim(int a, int b)
{
    if(a < b) return a;
    return b;
}

inline char getChar(FILE *fin)
{
    if(pos == BUF_SIZE)
    {
        fread(buf,1,BUF_SIZE,fin);
        pos = 0;
    }
    return buf[pos++];
}

inline int read(FILE *fin)
{
    int rez = 0;
    char c;
    do
    {
        c = getChar(fin);
    }while(!isdigit(c));
    do
    {
        rez = 10*rez + c-'0';
        c = getChar(fin);
    }while(isdigit(c));
    return rez;
}

void buildTree(int low, int high, int pos)
{
    if(low == high)
    {
        segTree[pos] = v[low];
        return;
    }
    int mid = (low+high) >> 1;
    buildTree(low,mid,2*pos);
    buildTree(mid+1,high,2*pos+1);
    segTree[pos] = minim(segTree[2*pos], segTree[2*pos+1]);
}

int rangeMinQuery(int low, int high, int pos)
{
    if(a <= low && high <= b)
        return segTree[pos];
    if(a > high || b < low)
        return MAX_VALUE;
    int mid = (low+high) >> 1;
    return minim(rangeMinQuery(low,mid,2*pos), rangeMinQuery(mid+1,high,2*pos+1));
}

int main()
{
    int i, m;
    FILE *fin, *fout;
    fin = fopen("rmq.in","r");
    fout = fopen("rmq.out","w");
    n = read(fin);
    m = read(fin);
    for(i=1; i<=n; i++)
        v[i] = read(fin);
    buildTree(1,n,1);
    for(i=1; i<=m; i++)
    {
        a = read(fin);
        b = read(fin);
        fprintf(fout,"%d\n",rangeMinQuery(1,n,1));
    }
    fclose(fin);
    fclose(fout);
    return 0;
}