Cod sursa(job #1249323)

Utilizator nytr0gennytr0gen nytr0gen Data 26 octombrie 2014 20:05:38
Problema Sortare prin comparare Scor 60
Compilator cpp Status done
Runda Arhiva educationala Marime 1.31 kb
#include <cstdio>
using namespace std;

const int NMAX = 500000;

inline int get_digit(const int value, const int base, const int exp) {
    return (value / exp) % base;
}

void radix_sort(int *A, const int len) {
    const int BASE = 1024;

    // max_A element
    int max_A = A[0], i;
    for (i = 1; i < len; i++)
        if (A[i] > max_A) max_A = A[i];

    int B[NMAX];
    for (int exp = 1; exp < max_A; exp *= BASE) {
        int bucket[BASE] = {0};

        // Count elements by digit
        for (i = 0; i < len; i++)
            bucket[ get_digit(A[i], BASE, exp) ]++;

        // Add the count from behind to use later in ordering
        for (i = 1; i < BASE; i++)
            bucket[i] += bucket[i-1];

        // Put elements in order
        for (i = len-1; i >= 0; i--)
            B[ --bucket[ get_digit(A[i], BASE, exp) ] ] = A[i];

        // Copy elements from B to A
        for (i = 0; i < len; i++)
            A[i] = B[i];
    }
}

int main() {
    int n, v[NMAX];

    FILE * in = fopen("algsort.in", "r");
    fscanf(in, "%d", &n);
    for (int i = 0; i < n; ++i)
        fscanf(in, "%d", &v[i]);
    fclose(in);

    radix_sort(v, n);

    FILE * out = fopen("algsort.out", "w");
    for (int i = 0; i < n; ++i)
        fprintf(out, "%d ", v[i]);
        //printf("%d ", v[i]);
    fclose(out);

    return 0;
}