go & python implementation

34. Find First and Last Position of Element in Sorted Array/findBoth/findBoth.go

@@ -0,0 +1,40 @@
+package findboth
+
+func bisecLeft(nums []int, target int) int {
+	left, right := 0, len(nums)
+	var mid int
+	for left < right {
+		mid = (left + right) / 2
+		if nums[mid] < target {
+			left = mid + 1
+		} else {
+			right = mid
+		}
+	}
+	return left
+}
+
+func bisecRight(nums []int, target int) int {
+	left, right := 0, len(nums)
+	var mid int
+	for left < right {
+		mid = (left + right) / 2
+		if nums[mid] <= target {
+			left = mid + 1
+		} else {
+			right = mid
+		}
+	}
+	return left
+}
+
+func searchRange(nums []int, target int) []int {
+
+	left := bisecLeft(nums, target)
+	if left == len(nums) ||
+		nums[left] != target {
+		return []int{-1, -1}
+	}
+	right := bisecRight(nums[left+1:], target)
+	return []int{left, left + right}
+}

34. Find First and Last Position of Element in Sorted Array/main.py

@@ -0,0 +1,11 @@
+from bisect import bisect, bisect_left
+
+
+class Solution:
+    def searchRange(self, nums: List[int], target: int) -> List[int]:
+        left = bisect_left(nums, target)
+        if left != len(nums) and nums[left] == target:
+            right = bisect(nums, target, left)
+            return left, right - 1
+        else:
+            return -1, -1

34. Find First and Last Position of Element in Sorted Array/onlyFindLeft/findLeftSoln.go

@@ -0,0 +1,31 @@
+package findleft
+
+/* merely 1 function. merely find left
+cannot judge in besecLeft() whether nums[left]==target
+because we search target+1 to get the right position
+*/
+
+func bisecLeft(nums []int, target int) int {
+	// 这个函数相当于 python中的bisect.bisect_left
+	left, right := 0, len(nums)
+	var mid int
+	for left < right {
+		mid = (left + right) / 2
+		if nums[mid] < target {
+			left = mid + 1
+		} else {
+			right = mid
+		}
+	}
+	return left
+}
+
+func searchRange(nums []int, target int) []int {
+	left := bisecLeft(nums, target)
+	if left == len(nums) ||
+		nums[left] != target {
+		return []int{-1, -1}
+	}
+	right := bisecLeft(nums[left+1:], target+1)
+	return []int{left, left + right}
+}