Create firstAndLastPositionElementSortedArray.java

firstAndLastPositionElementSortedArray.java

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+class Solution {
+    public int[] searchRange(int[] arr, int target) {
+        int[] result = {-1,-1};
+
+        if (arr == null || arr.length == 0) {
+            return result;
+        }
+
+        int left = binarySearchLeft(arr,target);
+        int right = binarySearchRight(arr,target);
+
+        result[0]= left;
+        result[1] = right;
+
+        return result;
+    }
+
+    public int binarySearchLeft(int[] arr, int target){
+        int left=0;
+        int right = arr.length-1;
+        int result = -1;
+
+        while(left<=right){
+            int mid = (left+right)/2;
+
+            if(arr[mid] == target){
+                result=mid;
+                right = mid-1;
+            }
+            else if (arr[mid] < target){
+                left=mid+1;
+            }else{
+                right=mid-1;
+            }
+        }
+        return result;
+    }
+
+    public int binarySearchRight(int[] arr, int target){
+        int left=0;
+        int right = arr.length-1;
+        int result = -1;
+
+        while(left<=right){
+            int mid = (left+right)/2;
+
+            if(arr[mid] == target){
+                result=mid;
+                left = mid+1;
+            }
+            else if (arr[mid] < target){
+                left=mid+1;
+            }else{
+                right=mid-1;
+            }
+        }
+        return result;
+    }
+}