Merge sort
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The document contains a C program that implements the merge sort algorithm, including its main function for reading user input, sorting an array, and displaying the results. It details the process of merging sorted subarrays and uses a temporary array to store results before copying back to the original array. The program also includes user interaction for entering the number of elements and the elements themselves.
![/*** program of merge sort ****
* http://www.tutorial4us.com/data-structure/c-merge-sort */
#include<stdio.h>
#include<conio.h>
void mergesort(int a[],int n)
{
int b[50],c,low1,high1,high2,low2;
int i,k,j;
c=1;
while(c<n)
{
low1=0;
k=0;
while(low1+c<n)
{
low2=low1+c ;
high1=low2-1;
if(low2+c-1<n)
high2=low2+c-1;
else
high2=n-1;
i=low1;](https://image.slidesharecdn.com/merge-sort-150824004148-lva1-app6891/85/Merge-sort-1-320.jpg)
![j=low2;
while(i<=high1 && j<=high2)
{
if(a[i]<=a[j])
b[k++]=a[i++];
else
b[k++]=a[j++];
}
while(i<=high1)
b[k++]=a[i++];
while(j<=high2)
b[k++]=a[j++];
low1=high2+1;
}
i=low1;
while(k<n)
b[k++]=a[i++];
for(i=0; i<n; i++)
a[i]=b[i];
c=c*2;
}
}
main()](https://image.slidesharecdn.com/merge-sort-150824004148-lva1-app6891/85/Merge-sort-2-320.jpg)
![{
int a[20],i,n;
clrscr();
printf("How many elements you want to enter: ");
scanf("%d",&n);
printf("Enter any %d elements: n",n);
for(i=0; i<n; i++)
{
scanf("%d",&a[i]);
}
printf("nnList Befor Sorting : ");
for(i=0; i<n; i++)
{
delay(400);
printf("%5d",a[i]);
}
mergesort(a,n);
printf("nnList After Sorting : ");
for(i=0; i<n; i++)
{
delay(400);
printf("%5d",a[i]);](https://image.slidesharecdn.com/merge-sort-150824004148-lva1-app6891/85/Merge-sort-3-320.jpg)
Merge sort
- 1. /*** program of merge sort **** * http://www.tutorial4us.com/data-structure/c-merge-sort */ #include<stdio.h> #include<conio.h> void mergesort(int a[],int n) { int b[50],c,low1,high1,high2,low2; int i,k,j; c=1; while(c<n) { low1=0; k=0; while(low1+c<n) { low2=low1+c ; high1=low2-1; if(low2+c-1<n) high2=low2+c-1; else high2=n-1; i=low1;
- 2. j=low2; while(i<=high1 && j<=high2) { if(a[i]<=a[j]) b[k++]=a[i++]; else b[k++]=a[j++]; } while(i<=high1) b[k++]=a[i++]; while(j<=high2) b[k++]=a[j++]; low1=high2+1; } i=low1; while(k<n) b[k++]=a[i++]; for(i=0; i<n; i++) a[i]=b[i]; c=c*2; } } main()
- 3. { int a[20],i,n; clrscr(); printf("How many elements you want to enter: "); scanf("%d",&n); printf("Enter any %d elements: n",n); for(i=0; i<n; i++) { scanf("%d",&a[i]); } printf("nnList Befor Sorting : "); for(i=0; i<n; i++) { delay(400); printf("%5d",a[i]); } mergesort(a,n); printf("nnList After Sorting : "); for(i=0; i<n; i++) { delay(400); printf("%5d",a[i]);