Answer:
Explanation:
MERGE SORT
#include<stdlib.h>
#include<stdio.h>
#include<string.h>
void merge(int arr[], int l, int m, int r)
{
int i, j, k;
int n1 = m - l + 1;
int n2 = r - m;
int L[n1], R[n2];
for (i = 0; i < n1; i++)
L[i] = arr[l + i];
for (j = 0; j < n2; j++)
R[j] = arr[m + 1+ j];
i = 0;
j = 0;
k = l;
while (i < n1 && j < n2)
{
if (L[i] <= R[j])
{
arr[k] = L[i];
i++;
}
else
{
arr[k] = R[j];
j++;
}
k++;
}
while (i < n1)
{
arr[k] = L[i];
i++;
k++;
}
while (j < n2)
{
arr[k] = R[j];
j++;
k++;
}
}
void mergeSort(int arr[], int l, int r)
{
if (l < r)
{
int m = l+(r-l)/2;
mergeSort(arr, l, m);
mergeSort(arr, m+1, r);
merge(arr, l, m, r);
}
}
void printArray(int A[], int size)
{
int i;
for (i=0; i < size; i++)
printf("%d ", A[i]);
printf("\n");
}
int main()
{
int arr[1000] = {0};
int arr_size =0;
int data;
char file1[20];
strcpy(file1,"data.txt");
FILE *fp;
fp = fopen(file1,"r+");
if (fp == NULL) // if file not opened return error
{
perror("Unable to open file");
return -1;
}
else
{
fscanf (fp, "%d", &data);
arr[arr_size]=data;
arr_size++;
while (!feof (fp))
{
fscanf (fp, "%d", &data);
arr[arr_size]=data;
arr_size++;
}
}
printf("Given array is \n");
printArray(arr, arr_size);
mergeSort(arr, 0, arr_size - 1);
printf("\nSorted array Using MERGE SORT is \n");
printArray(arr, arr_size);
return 0;
}
