add step4 for Search Insert Position

Author: rihib

pullrequests/search_insert_position/step4.go

@@ -0,0 +1,15 @@
+//lint:file-ignore U1000 Ignore all unused code
+package searchinsertposition
+
+func searchInsert(nums []int, target int) int {
+	left, right := 0, len(nums)
+	for left < right {
+		mid := left + (right-left)/2
+		if nums[mid] < target {
+			left = mid + 1
+		} else {
+			right = mid
+		}
+	}
+	return left
+}