binary search with insertion sort

Question

Will find value using binary search using insertion sort. New to coding so cant find the solution. Now if I input any values it doesn't use insertion and can't find the value.

#include <stdio.h>
int main()
{
int i, low, high, mid, n, key, array[100],size;
printf("Enter number of elements");
scanf("%d",&n);
printf("Enter %d integersn", n);
for(i = 0; i <= n-1; i++)
scanf("%d",&array[i]);
void insertionSort(int array[], int size) {
 for (int step = 1; step <= size-1; step++) {
   int key = array[step];
   int j = step - 1;

   while (key < array[j] && j >= 0) {
     array[j + 1] = array[j];
     --j;
   }
   array[j + 1] = key;
 }
}
  printf("%d\n",key);
  scanf("%d", &key);
  low = 0;
  high = n - 1;
  mid = (low+high)/2;
  while (low <= high) {
  if(array[mid] < key)
  low = mid + 1;
  else if (array[mid] == key) {
  printf("%d\n", key, mid+1);
  break;
}
  else
  high = mid - 1;
  mid = (low + high)/2;
}
  if(low > high)
  printf("%d\n", key);
  return 0;
}

Answer 1

The problem is that insertionSort is never called on the array after inputting the elements. Instead, you have defined the function insertionSort at the point where it should have been called. Defining a function within another function is not a standard part of the C language, but some compilers may support it as an extension.

If you move the definition of insertionSort outside the main function, and add a call to the function, the code works after fixing a few printf statements. Here is a slightly tidied up, working version:

#include <stdio.h>

void insertionSort(int array[], int size) {
  for (int step = 1; step <= size-1; step++) {
    int key = array[step];
    int j = step - 1;

    while (key < array[j] && j >= 0) {
      array[j + 1] = array[j];
      --j;
    }
    array[j + 1] = key;
  }
}

int main()
{
  int i, low, high, mid, n, key, array[100],size;
  printf("Enter number of elements: ");
  scanf("%d",&n);
  printf("Enter %d integers: ", n);
  for(i = 0; i <= n-1; i++)
    scanf("%d",&array[i]);
  insertionSort(array, n);
  printf("Enter key: ");
  scanf("%d", &key);
  low = 0;
  high = n - 1;
  mid = (low+high)/2;
  while (low <= high) {
    if(array[mid] < key)
      low = mid + 1;
    else if (array[mid] == key) {
      printf("%d found at %d\n", key, mid+1);
      break;
    }
    else
      high = mid - 1;
    mid = (low + high)/2;
  }
  if(low > high)
    printf("%d not found\n", key);
  return 0;
}