Cod sursa(job #3218422)

Utilizator deerMohanu Dominic deer Data 27 martie 2024 10:24:02
Problema Range minimum query Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 2.91 kb
#include <bits/stdc++.h>
const int NMAX = 1e5;
const int lgmax = 17;
using namespace std;
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 != '-');
		int sgn = 1;
		if (c == '-') {
			n = 0;
			sgn = -1;
		} else {
			n = c - '0';
		}
		while (isdigit(c = read_ch())) {
			n = 10 * n + c - '0';
		}
		n *= sgn;
		return *this;
	}

	InParser& operator >> (long long &n) {
		char c;
		n = 0;
		while (!isdigit(c = read_ch()) && c != '-');
		long long sgn = 1;
		if (c == '-') {
			n = 0;
			sgn = -1;
		} else {
			n = c - '0';
		}
		while (isdigit(c = read_ch())) {
			n = 10 * n + c - '0';
		}
		n *= sgn;
		return *this;
	}
};

class OutParser {
private:
    FILE *fout;
    char *buff;
    int sp;

    void write_ch(char ch) {
        if (sp == 50000) {
            fwrite(buff, 1, 50000, fout);
            sp = 0;
            buff[sp++] = ch;
        } else {
            buff[sp++] = ch;
        }
    }


public:
    OutParser(const char* name) {
        fout = fopen(name, "w");
        buff = new char[50000]();
        sp = 0;
    }
    ~OutParser() {
        fwrite(buff, 1, sp, fout);
        fclose(fout);
    }

    OutParser& operator << (int vu32) {
        if (vu32 <= 9) {
            write_ch(vu32 + '0');
        } else {
            (*this) << (vu32 / 10);
            write_ch(vu32 % 10 + '0');
        }
        return *this;
    }

    OutParser& operator << (long long vu64) {
        if (vu64 <= 9) {
            write_ch(vu64 + '0');
        } else {
            (*this) << (vu64 / 10);
            write_ch(vu64 % 10 + '0');
        }
        return *this;
    }

    OutParser& operator << (char ch) {
        write_ch(ch);
        return *this;
    }
    OutParser& operator << (const char *ch) {
        while (*ch) {
            write_ch(*ch);
            ++ch;
        }
        return *this;
    }
};
InParser fin ("rmq.in");
OutParser fout ("rmq.out");
int arr[NMAX + 5], spt[lgmax][NMAX], lg2[NMAX + 5], n, q, st, dr;
void build(){
    for (int i = 1; i <= lg2[n]; i++)
        for (int j = (1 << i); j <= n; j++)
            spt[i][j] = min(spt[i - 1][j - (1 << (i - 1))], spt[i - 1][j]);
}
int query(int l, int r){
    int ordin = lg2[r - l + 1];
    int p = (1 << ordin);
    return min(spt[ordin][l + p - 1], spt[ordin][r]);
}
signed main(){
    fin >> n >> q;
    lg2[0] = -1;
    for (int i = 1; i <= n; i++)
         fin >> arr[i], spt[0][i] = arr[i], lg2[i] = lg2[i >> 1] + 1;
    build();
    while(q--)
        fin >> st >> dr, fout << query(st, dr) << "\n";
    return 0;
}