Simple c program for mergesort

Answer 1

#include

#include

#define MAX_ARY 10

void merge_sort(int x[], int end, int start);

int main(void) {

int ary[MAX_ARY];

int j = 0;

printf("\n\nEnter the elements to be sorted: \n");

for(j=0;j scanf("%d",&ary[j]);

/* array before mergesort */

printf("Before :");

for(j = 0; j < MAX_ARY; j++)

printf(" %d", ary[j]);

printf("\n");

merge_sort(ary, 0, MAX_ARY - 1);

/* array after mergesort */

printf("After Merge Sort :");

for(j = 0; j < MAX_ARY; j++)

printf(" %d", ary[j]);

printf("\n");

getch();

}

/* Method to implement Merge Sort*/

void merge_sort(int x[], int end, int start) {

int j = 0;

const int size = start - end + 1;

int mid = 0;

int mrg1 = 0;

int mrg2 = 0;

int executing[MAX_ARY];

if(end == start)

return;

mid = (end + start) / 2;

merge_sort(x, end, mid);

merge_sort(x, mid + 1, start);

for(j = 0; j < size; j++)

executing[j] = x[end + j];

mrg1 = 0;

mrg2 = mid - end + 1;

for(j = 0; j < size; j++) {

if(mrg2 <= start - end)

if(mrg1 <= mid - end)

if(executing[mrg1] > executing[mrg2])

x[j + end] = executing[mrg2++];

else

x[j + end] = executing[mrg1++];

else

x[j + end] = executing[mrg2++];

else

x[j + end] = executing[mrg1++];

}

}

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