Cod sursa(job #1315563)

Utilizator Denisa13Stefan Denisa Denisa13 Data 12 ianuarie 2015 21:55:40
Problema Sortare prin comparare Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.96 kb
#include<iostream>
#include <fstream>
using namespace std;
ifstream f("algsort.in");
ofstream g("algsort.out");
// A utility function to get maximum value in arr[]
int getMax(unsigned long arr[], unsigned long n)
{
    int mx = arr[0];
    for (int i = 1; i < n; i++)
        if (arr[i] > mx)
            mx = arr[i];
    return mx;
}

// A function to do counting sort of arr[] according to
// the digit represented by exp.
void countSort(unsigned long arr[], unsigned long n, unsigned long exp)
{
    int output[n]; // output array
    int i, count[10] = {0};

    // Store count of occurrences in count[]
    for (i = 0; i < n; i++)
        count[ (arr[i]/exp)%10 ]++;

    // Change count[i] so that count[i] now contains actual position of
    // this digit in output[]
    for (i = 1; i < 10; i++)
        count[i] += count[i - 1];

    // Build the output array
    for (i = n - 1; i >= 0; i--)
    {
        output[count[ (arr[i]/exp)%10 ] - 1] = arr[i];
        count[ (arr[i]/exp)%10 ]--;
    }

    // Copy the output array to arr[], so that arr[] now
    // contains sorted numbers according to curent digit
    for (i = 0; i < n; i++)
        arr[i] = output[i];
}

// The main function  that sorts arr[] of size n using Radix Sort
void radixsort(unsigned long arr[], unsigned long n)
{
    // Find the maximum number to know number of digits
    int m = getMax(arr, n);

    // Do counting sort for every digit. Note that instead of passing digit
    // number, exp is passed. exp is 10^i where i is current digit number
    for (unsigned long exp = 1; m/exp > 0; exp *= 10)
        countSort(arr, n, exp);
}


void print(unsigned long arr[], unsigned long n)
{
    for (unsigned long i = 0; i < n; i++)
        g << arr[i] << " ";
}


int main()
{
    unsigned long arr[500001], n;
    f>>n;
    for (unsigned long i = 0; i < n; i++)
        f>> arr[i];

    radixsort(arr, n);
    print(arr, n);
    return 0;
}