Cod sursa(job #2226001)

Utilizator Horia14Horia Banciu Horia14 Data 29 iulie 2018 09:11:13
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.61 kb
#include<cstdio>
#include<cctype>
#define MAX_N 100000
#define oo 0x7fffffff
#define BUF_SIZE 1 << 19
using namespace std;

int v[MAX_N+1], segTree[4*MAX_N+1], n, m, qlow, qhigh, pos = BUF_SIZE;
char buf[BUF_SIZE];

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 res = 0;
    char c;
    do {
        c = getChar(fin);
    }while(!isdigit(c));
    do {
        res = 10*res + c - '0';
        c = getChar(fin);
    }while(isdigit(c));
    return res;
}

inline int minim(int x, int y) {
    if(x <= y) return x;
    return y;
}

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

int minQuery(int low, int high, int pos) {
    if(qlow <= low && high <= qhigh)
        return segTree[pos];
    if(qlow > high || qhigh < low)
        return oo;
    int mid = (low + high) >> 1;
    return minim(minQuery(low,mid,2*pos),minQuery(mid+1,high,2*pos+1));
}

int main() {
    int i;
    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);
    buildSegmentTree(1,n,1);
    for(i = 1; i <= m; i++) {
        qlow = read(fin); qhigh = read(fin);
        fprintf(fout,"%d\n",minQuery(1,n,1));
    }
    fclose(fin);
    fclose(fout);
    return 0;
}