Merge pull request deutranium#181 from codelixir/master

Implemented binary search in golang

Author: codelixir

searchingAlgo/binarySearch/binarySearch.go

@@ -0,0 +1,45 @@
+package main
+
+import "fmt"
+
+// recursive implementation of binary search
+func binarySearch(arr []int, x, l, r int) (int, bool) {
+
+	// boundary condition
+	if l > r {
+		return -1, false
+	}
+
+	if mid := (r-l)/2 + l; arr[mid] == x { // when found, return the index
+		return mid, true
+	} else if arr[mid] < x {	// if query element is greater than the middle, search the right half
+		return binarySearch(arr, x, mid+1, r)
+	} else {					// if query element is less than the middle, search the left half
+		return binarySearch(arr, x, l, mid-1)
+	}
+}
+
+func main() {
+	fmt.Printf("Enter number of elements in array: ")
+	var n, x int
+	fmt.Scanf("%d", &n)
+
+	fmt.Printf("Enter the sorted array: ")
+	var arr []int
+	for i := 0; i < n; i++ {
+		var k int
+		fmt.Scanf("%d", &k)
+		arr = append(arr, k)
+	}
+
+	fmt.Printf("Enter the element to be searched: ")
+	fmt.Scanf("%d", &x)
+
+	idx, found := binarySearch(arr, x, 0, n-1)
+
+	if !found {
+		fmt.Printf("Element %d not found.\n", x)
+	} else {
+		fmt.Printf("Element %d found at position %d.\n", x, idx)
+	}
+}