From 5020e65ee8a1d216bfd33e1f9a787bae9d4444e8 Mon Sep 17 00:00:00 2001
From: Aadil <77232799+aadil42@users.noreply.github.com>
Date: Thu, 22 Jun 2023 18:59:40 +0530
Subject: [PATCH 1/3] Create
0034-find-first-and-last-position-of-element-in-sorted-array.js
Solved find-first-and-last-position-of-element-in-sorted-array in js.
---
...ast-position-of-element-in-sorted-array.js | 47 +++++++++++++++++++
1 file changed, 47 insertions(+)
create mode 100644 javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js
diff --git a/javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js b/javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js
new file mode 100644
index 000000000..da545a194
--- /dev/null
+++ b/javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js
@@ -0,0 +1,47 @@
+/**
+ * Binary Search
+ * https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array/
+ * Time O(log(n)) | Space O(1)
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number[]}
+ */
+var searchRange = function(nums, target) {
+
+ const result = [];
+
+ result.push(binarySearch(true));
+ result.push(binarySearch(false));
+
+ function binarySearch(leftBias) {
+ let left = 0;
+ let right = nums.length - 1;
+ let index = -1;
+
+ while(left <= right) {
+
+ const mid = Math.floor((left+right)/2);
+
+ if(target > nums[mid]) {
+ left = mid+1;
+ }
+ if(target < nums[mid]) {
+ right = mid-1;
+ }
+ // this is the meat of the code
+ if(target === nums[mid]) {
+ if(leftBias) {
+ index = mid;
+ right = mid - 1;
+ } else {
+ index = mid;
+ left = mid + 1;
+ }
+ }
+ }
+
+ return index;
+ }
+
+ return result;
+};
From b44ad1666937ca3a6e1acc53c46c4dd8fd109d47 Mon Sep 17 00:00:00 2001
From: Aadil <77232799+aadil42@users.noreply.github.com>
Date: Mon, 3 Jul 2023 20:19:10 +0530
Subject: [PATCH 2/3] Update
0034-find-first-and-last-position-of-element-in-sorted-array.js
Making variable names more descriptive.
---
...first-and-last-position-of-element-in-sorted-array.js | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js b/javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js
index da545a194..98b6bf729 100644
--- a/javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js
+++ b/javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js
@@ -13,7 +13,7 @@ var searchRange = function(nums, target) {
result.push(binarySearch(true));
result.push(binarySearch(false));
- function binarySearch(leftBias) {
+ function binarySearch(isLeftBias) {
let left = 0;
let right = nums.length - 1;
let index = -1;
@@ -28,9 +28,10 @@ var searchRange = function(nums, target) {
if(target < nums[mid]) {
right = mid-1;
}
- // this is the meat of the code
- if(target === nums[mid]) {
- if(leftBias) {
+
+ const isTarget = target === nums[mid];
+ if(isTarget) {
+ if(isLeftBias) {
index = mid;
right = mid - 1;
} else {
From fe9c7060890c04249e64d6f6bd2a4d8289146d5c Mon Sep 17 00:00:00 2001
From: Aadil <77232799+aadil42@users.noreply.github.com>
Date: Sat, 22 Jul 2023 16:25:04 +0530
Subject: [PATCH 3/3] Update
0034-find-first-and-last-position-of-element-in-sorted-array.js
Using the bitwise operator and removing the inner function.
---
...-last-position-of-element-in-sorted-array.js | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js b/javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js
index 98b6bf729..c11490e11 100644
--- a/javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js
+++ b/javascript/0034-find-first-and-last-position-of-element-in-sorted-array.js
@@ -10,17 +10,20 @@ var searchRange = function(nums, target) {
const result = [];
- result.push(binarySearch(true));
- result.push(binarySearch(false));
+ result.push(binarySearch(true, nums, target));
+ result.push(binarySearch(false, nums, target));
- function binarySearch(isLeftBias) {
+ return result;
+};
+
+var binarySearch = (isLeftBias, nums, target) => {
let left = 0;
let right = nums.length - 1;
let index = -1;
while(left <= right) {
- const mid = Math.floor((left+right)/2);
+ const mid = (left + right) >> 1;
if(target > nums[mid]) {
left = mid+1;
@@ -40,9 +43,5 @@ var searchRange = function(nums, target) {
}
}
}
-
return index;
- }
-
- return result;
-};
+}