mergesort.c

A order algoritm comparison by the C time(). Comparison beetwen : insort,selection sort,mergesort,

/*------------------------------------
 * Algoritmo di riordino merge sort
 */

#include "misc.h"


void sort(int A[], int min, int max) {
   if (min < max) {
   int Mid = (min+max)/2;
   sort(A,min,Mid);
   sort(A,Mid+1,max);
   merge(A,min,Mid,max);               
   }
}  /* sort */


int merge(int A[], int p, int q,int r) {

       int B[r-p+1];
        int i = p;
        int j = q+1;
        int k = 0;

        while ( (i <= q) && (j <= r) ) {
                if (A[i] < A[j])
                        B[k] = A[i++];
                else 
                        B[k] = A[j++];
                k++;
        }

        while (i <= q)
                B[k++] = A[i++];
        
        while (j <= r)
                B[k++] = A[j++];
        
        for (i=0; i<r-p+1; i++)
                A[p+i] = B[i];

}  /* merge */