Week 4 Array

dsa-pros/leetcode/array/JavaScript/JuwonAdeyemi/ArrayWeek4.js

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+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ *
+ * Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.
+ */
+var containsDuplicate = function (nums) {
+  nums.sort();
+  for (let i = 0; i <= nums.length - 1; i++) {
+    if (nums[i] === nums[i + 1]) {
+      return true;
+    }
+  }
+  return false;
+};
+
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number}
+ * 
+ * Given an array of integers nums which is sorted in ascending order, and an integer target, write a function to search target in nums. If target exists, then return its index. Otherwise, return -1.
+
+You must write an algorithm with O(log n) runtime complexity.
+
+
+ */
+var search = function (nums, target) {
+  for (let i = 0; i < nums.length; i++) {
+    if (nums[i] > nums[i + 1]) {
+      // Swap elements
+      var temp = nums[i];
+      nums[i] = nums[i + 1];
+      nums[i + 1] = temp;
+    }
+
+    if (nums[i] === target) {
+      return i;
+    }
+  }
+  return -1; // Element not found
+};
+
+/**
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {void} Do not return anything, modify nums in-place instead.
+ * Given an integer array nums, rotate the array to the right by k steps, where k is non-negative.
+ */
+var rotate = function (nums, k) {
+  k %= nums.length; // actual number of steps to rotate
+  nums.unshift(...nums.splice(-k));
+};
+
+/**
+ * @param {number[]} nums
+ * @return {number}
+ * Given an integer array nums, return the length of the longest strictly increasing 
+subsequence
+.
+ */
+var lengthOfLIS = function (nums) {
+  let count = 1;
+  for (let i = 0; i < nums.length - 1; i++) {
+    if (nums[i + 1] > nums[i]) {
+      count++;
+    }
+  }
+  return count;
+};