added a binary search code

Author: akiii1997

Search/BinarySearch/c/BS.c

@@ -0,0 +1,83 @@
+#include <stdio.h>
+
+#define MAX 20
+
+// array of items on which linear search will be conducted. 
+int intArray[MAX] = {1,2,3,4,6,7,9,11,12,14,15,16,17,19,33,34,43,45,55,66};
+
+void printline(int count) {
+   int i;
+	
+   for(i = 0;i <count-1;i++) {
+      printf("=");
+   }
+	
+   printf("=\n");
+}
+
+int find(int data) {
+   int lowerBound = 0;
+   int upperBound = MAX -1;
+   int midPoint = -1;
+   int comparisons = 0;      
+   int index = -1;
+	
+   while(lowerBound <= upperBound) {
+      printf("Comparison %d\n" , (comparisons +1) );
+      printf("lowerBound : %d, intArray[%d] = %d\n",lowerBound,lowerBound,
+         intArray[lowerBound]);
+      printf("upperBound : %d, intArray[%d] = %d\n",upperBound,upperBound,
+         intArray[upperBound]);
+      comparisons++;
+		
+      // compute the mid point
+      // midPoint = (lowerBound + upperBound) / 2;
+      midPoint = lowerBound + (upperBound - lowerBound) / 2;	
+		
+      // data found
+      if(intArray[midPoint] == data) {
+         index = midPoint;
+         break;
+      } else {
+         // if data is larger 
+         if(intArray[midPoint] < data) {
+            // data is in upper half
+            lowerBound = midPoint + 1;
+         }
+         // data is smaller 
+         else {
+            // data is in lower half 
+            upperBound = midPoint -1;
+         }
+      }               
+   }
+   printf("Total comparisons made: %d" , comparisons);
+   return index;
+}
+
+void display() {
+   int i;
+   printf("[");
+	
+   // navigate through all items 
+   for(i = 0;i<MAX;i++) {
+      printf("%d ",intArray[i]);
+   }
+	
+   printf("]\n");
+}
+
+void main() {
+   printf("Input Array: ");
+   display();
+   printline(50);
+	
+   //find location of 1
+   int location = find(55);
+
+   // if element was found 
+   if(location != -1)
+      printf("\nElement found at location: %d" ,(location+1));
+   else
+      printf("\nElement not found.");
+}