fork download
copy 
  1. #include <stdio.h>
  2. #include <stdlib.h>
  3. #include <string.h>
  4. #include <math.h>
  5.  
  6. #define EPS 1E-6
  7.  
  8. int compare_newdouble(const void *left, const void *right);
  9. void mergesort(void *base, size_t n, size_t size, int (*compar)(const void *, const void *));
  10.  
  11.  
  12.  
  13. int compare_newdouble(const void *left, const void *right)
  14. {
  15.     double *p = (double*)left;
  16.     double *q = (double*)right;
  17.  
  18.     if(fabs(fabs(*p) - fabs(*q)) < EPS)
  19.     {
  20.         return 0;
  21.     }
  22.  
  23.     if(fabs(*p) > fabs(*q))
  24.     {
  25.         return 1;
  26.     }
  27.  
  28.     return -1;
  29. }
  30.  
  31. void mergesort(void *base, size_t n, size_t size, int (*compar)(const void *, const void *))
  32. {
  33.     const size_t mid = n/2;
  34.     size_t l = 0, r = 0, a = 0;
  35.     size_t i;
  36.     void *add=malloc(size*n);
  37.  
  38.     if(n < 2)
  39.     {
  40.         return;
  41.     }
  42.  
  43.     mergesort(base, mid, size, compar); //left array
  44.     mergesort(base+size*mid, n-mid, size, compar); //right array
  45.  
  46.     while(l < mid && r < (n-mid))
  47.     {
  48.         if((*compar)(base+size*l, base+size*mid+size*r) == -1)
  49.         {
  50.             memcpy((add+size*a), (base+size*l), size); // putting the memory from left to add
  51.             a++;
  52.             l++;
  53.         }
  54.         else
  55.         {
  56.             memcpy((add+size*a), (base+size*mid+size*r), size); // putting the memory from right to add
  57.             a++;
  58.             r++;
  59.         }
  60.     }
  61.  
  62.     // Здесь были циклы
  63.  
  64.     if(l < mid)
  65.     {
  66.         memcpy((add+size*a), (base+size*l), size * (mid - l));
  67.     }
  68.     else if(r < (n-mid))
  69.     {
  70.         memcpy((add+size*a), (base+size*mid+size*r), size * (n-mid - r));
  71.  
  72.     }
  73.  
  74.     memcpy(base, add, size*n);
  75.  
  76.     free(add);
  77. }
  78.  
  79. int main(void)
  80. {
  81.     int n = 15, i;
  82.     double *a;
  83.  
  84.     a=malloc(sizeof(double)*n);
  85.  
  86.     for(i = 0; i < n; i++)
  87.     {
  88.         a[i] = n - i;
  89.     }
  90.  
  91.     mergesort(a, n, sizeof(double), &compare_newdouble);
  92.  
  93.     for(i = 0; i < n; i++)
  94.     {
  95.         printf("%lf ", a[i]);
  96.     }
  97.  
  98.     free(a);
  99.  
  100.     return 0;
  101. }
  102.  
Success #stdin #stdout 0s 2244KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
1.000000 2.000000 3.000000 4.000000 5.000000 6.000000 7.000000 8.000000 9.000000 10.000000 11.000000 12.000000 13.000000 14.000000 15.000000
https://ideone.com/3UMQTC
language:
C (gcc 8.3)
created:
9 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!