Update 0034.在排序数组中查找元素的第一个和最后一个位置.md

problems/0034.在排序数组中查找元素的第一个和最后一个位置.md

@@ -329,6 +329,67 @@ class Solution {
 }
 ```
 
+### C#
+
+```c#
+public int[] SearchRange(int[] nums, int target) {
+
+	var leftBorder = GetLeftBorder(nums, target);
+	var rightBorder = GetRightBorder(nums, target);
+	
+	if (leftBorder == -2 || rightBorder == -2) {
+		return new int[] {-1, -1};
+	}
+	
+	if (rightBorder - leftBorder >=2) {
+		return new int[] {leftBorder + 1, rightBorder - 1};
+	}
+	
+	return new int[] {-1, -1};
+
+}
+
+public int GetLeftBorder(int[] nums, int target){
+	var left = 0;
+	var right = nums.Length - 1;
+	var leftBorder = -2;
+	
+	while (left <= right) {
+		var mid = (left + right) / 2;
+		
+		if (target <= nums[mid]) {
+			right = mid - 1;
+			leftBorder = right;
+		}
+		else {
+			left = mid + 1;
+		}
+	}
+	
+	return leftBorder;
+}
+
+public int GetRightBorder(int[] nums, int target){
+	var left = 0;
+	var right = nums.Length - 1;
+	var rightBorder = -2;
+	
+	while (left <= right) {
+		var mid = (left + right) / 2;
+		
+		if (target >= nums[mid]) {
+			left = mid + 1;
+			rightBorder = left;
+		}
+		else {
+			right = mid - 1;
+		}
+	}
+	
+	return rightBorder;
+}
+```
+
 
 
 ### Python