Cod sursa(job #2811693)

Utilizator cdenisCovei Denis cdenis Data 2 decembrie 2021 21:46:18
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.6 kb
#include <iostream>
#include <fstream>
#include <stdio.h>
#include <ctype.h>

class InParser {
private:
	FILE *fin;
	char *buff;
	int sp;

	char read_ch() {
		++sp;
		if (sp == 4096) {
			sp = 0;
			fread(buff, 1, 4096, fin);
		}
		return buff[sp];
	}

public:
	InParser(const char* nume) {
		fin = fopen(nume, "r");
		buff = new char[4096]();
		sp = 4095;
	}

	InParser& operator >> (int &n) {
		char c;
		while (!isdigit(c = read_ch()) && c != '-');
        n = c - '0';
		while (isdigit(c = read_ch())) {
			n = 10 * n + c - '0';
		}
		return *this;
	}
};

using namespace std;

int n,m,pos,st,dr,val,tree[400010],type,minim;

void update(int node, int left, int right)
{
    if(left==right)
    {
        tree[node]=val;
        return;
    }
    int mid=(left+right)/2;
    if(pos<=mid)
        update(2*node,left,mid);
    else
        update(2*node+1,mid+1,right);
    tree[node]=min(tree[2*node],tree[2*node+1]);
}

void query(int node, int left, int right)
{
    if(st<=left && right<=dr)
    {
        if(minim>tree[node])
            minim=tree[node];
        return;
    }
    int mid=(left+right)/2;
    if(st<=mid)
        query(2*node,left,mid);
    if(mid<dr)
        query(2*node+1,mid+1,right);
}

int main()
{
    InParser fin("rmq.in");
    ofstream fout("rmq.out");
    fin >> n >> m;
    for(int i=1;i<=n;i++)
    {
        fin >> val;
        pos=i;
        update(1,1,n);
    }
    for(;m;--m)
    {
        fin >> st >> dr;
        minim=100005;
        query(1,1,n);
        fout << minim << '\n';
    }
    return 0;
}