updated binary search

C/algorithms/searching/binary_search.c

@@ -11,32 +11,46 @@
  */
 
 #include <stdio.h>
-#define SIZE 10
-int BinarySearch(int [],int);
-int main()
-{
-    int a[SIZE]={3,5,9,11,15,17,22,25,37,68},key,pos;
-    printf("Enter the Search Key\n");
-    scanf("%d",&key);
-    pos=BinarySearch(a,key);
-    if(pos==-1)
-    printf("The search key is not in the array\n");
-    else
-    printf("The search key %d is at location %d\n",key,pos);
-    return 0;    
+//function to perform binary search
+int binarySearch(int arr[], int size, int key) {
+    int low = 0, high = size - 1, mid;
+
+    while (low <= high) {
+        mid = (low + high) / 2;
+
+        if (arr[mid] == key)
+            return mid;
+        else if (key < arr[mid])
+            high = mid - 1;
+        else
+            low = mid + 1;
     }
 
-    int BinarySearch (int A[],int skey)
-    {
-    int low=0,high=SIZE-1,middle;
-    while (low <=high){
-         middle=(low+high)/2;
-         if(skey==A[middle])
-           return middle;
-         else if(skey <A[middle])
-                  high=middle-1;
-              else 
-                 low=middle+1;
-           }
-       return -1; 
-       }
+    return -1;
+}
+int main() {
+    int size, key, position;
+
+    printf("Enter the number of elements: ");
+    scanf("%d", &size);
+
+    int arr[size];
+
+    printf("Enter %d elements in ascending order:\n", size);
+    for (int i = 0; i < size; i++) {
+        scanf("%d", &arr[i]);
+    }
+
+    printf("Enter the number to search: ");
+    scanf("%d", &key);
+
+    position = binarySearch(arr, size, key);
+
+    if (position == -1)
+        printf("The number %d was not found in the array.\n", key);
+    else
+        printf("The number %d was found at index %d (position %d).\n", key, position, position + 1);
+
+    return 0;
+}
+