Cod sursa(job #1940809)

Utilizator savigunFeleaga Dragos-George savigun Data 26 martie 2017 20:23:39
Problema Range minimum query Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 2.61 kb
#include <bits/stdc++.h>
#define LOG(x) for(k=0;(1<<k)<=(x);k++);--k;
using namespace std;

class Reader
{
public:
    Reader() {}
    Reader(const char *file_name)
    {
        input_file = fopen(file_name, "r");
        cursor = 0;
        fread(buffer, SIZE, 1, input_file);
    }
    inline Reader &operator >>(int &n)
    {
        while(buffer[cursor] < '0' || buffer[cursor] > '9')
        {
            advance();
        }
        n = 0;
        while('0' <= buffer[cursor] && buffer[cursor] <= '9')
        {
            n = n * 10 + buffer[cursor] - '0';
            advance();
        }
        return *this;
    }
private:
    FILE *input_file;
    static const int SIZE = 1 << 17;
    int cursor;
    char buffer[SIZE];
    inline void advance()
    {
        ++ cursor;
        if(cursor == SIZE)
        {
            cursor = 0;
            fread(buffer, SIZE, 1, input_file);
        }
    }
};

class Writer
{
public:
    Writer(const char *name):
        m_stream(name)
    {
        memset(m_buffer, 0, sizeof(m_buffer));
        m_pos = 0;
    }

    Writer& operator<<(int a)
    {
        int many = 0;
        do
        {
            digit_buffer[many++] = a % 10 + '0';
            a /= 10;
        }
        while (a > 0);
        for (int i = many - 1; i >= 0; --i)
            putchar(digit_buffer[i]);
        return *this;
    }

    Writer& operator<<(const char *s)
    {
        for (; *s; ++s)
            putchar(*s);
        return *this;
    }

    ~Writer()
    {
        m_stream.write(m_buffer, m_pos);
    }

private:
    void putchar(char c)
    {
        m_buffer[m_pos++] = c;
        if (m_pos == kBufferSize)
        {
            m_stream.write(m_buffer, m_pos);
            m_pos = 0;
        }
    }

    static const int kBufferSize = 1 << 17;
    ofstream m_stream;
    char m_buffer[kBufferSize];
    char digit_buffer[30];
    int m_pos;
};

Reader in("rmq.in");
Writer out("rmq.out");

int n,m,k;
int RMQ[17][100001]= {0}, lg[100005];

void read_data()
{
    in>>n>>m;
    for(int i=1; i<=n; i++)  in>>RMQ[0][i];
}

inline void logs() {
    for (int i = 2; i <= n; ++i)
        lg[i] = lg[i / 2] + 1;
}

void compute()
{
    logs();
    for(int i=0; i<16; i++)
        for(int j=1; j<n-i; j++)
            RMQ[i+1][j]=min(RMQ[i][j],RMQ[i][j+(1<<i)]);
}

void answer()
{
    while(m--)
    {
        int x,y;
        in>>x>>y;
        k = lg[y-x+1];
        out<<min(RMQ[k][x],RMQ[k][y+1-(1<<k)])<<"\n";
    }
}

int main()
{
    read_data();
    compute();
    answer();
}