Binary_Search.c

C/Binary_Search.c

@@ -0,0 +1,45 @@
+//Program to perform binary search on an array
+#include <stdio.h>
+#include <stdlib.h>
+
+// A comparator function used by qsort 
+int compare(const void * a, const void * b) 
+{ 
+    return ( *(int*)a - *(int*)b ); 
+} 
+
+int main() {
+   int n,s,i,low,high,mid,A[1000];
+   printf("Enter the number of elements");
+   scanf("%d",&n);
+
+   printf("Enter the elements of array");
+   for(i=0;i<n;i++)
+   {
+       scanf("%d",&A[i]);
+   }
+
+   printf("Enter the element to be searched");
+   scanf("%d",&s);
+
+   qsort(A, n, sizeof(int), compare);   //Binary search is applicable only on           sorted array
+   low=0;
+   high=n-1;                           //Initially our search space is the whole        array
+   while(low<=high)
+   {
+       mid=low+((high-low)/2);
+       if(A[mid]==s)
+            break;
+        else if(A[mid]>s)           // The element we are searching lies on the left side of middle element
+            high=mid-1;
+        else
+            low=mid+1;             // The element we are searching lies on the right side of middle element
+   }
+
+    if(low<=high)
+        printf("Element is present at index %d",mid);
+    else
+        printf("Element not present in the array");
+
+   return 0;
+}