Egbert Lin's Blog

Basic programming - Heap Sort

Approach:

Heap is a complete binary tree. And, heap feature is that parent node must bigger than its child nodes. It also calls max-heap.

Basic programming - Merge Sort

Approach:

It is a Divide and Conquer problem. Divide the vector into small group to sort, and merge each small groups to the vector.

Basic programming - Quick Sort

Approach:

Take one element as the pivot to separate two parts from another elements. For the convenient, we always takes the last element as the pivot.

Basic programming - Bubble Sort

Approach:

Compare with each elements in the range [0: n] and if vector[i] is bigger than vector[i + 1], call swap().

Basic programming - Insertion Sort

Approach:

Need to use two for-loop. One is unsorted data in the range [i:n] and the other is sorted data in the range [0:i].

Take one element from unsorted data to compare with sorted data.
Step 1: use temp variable to store this element
Step 2: search value from sorted data which is bigger than temp , if true, move the bigger value to current position vector[j] = vector[j - 1]
Step 3: Until if-statement returns false, it means the value of j - 1 is smaller than temp, so insert temp to current position vector[j] = temp.

23. Merge k Sorted Lists

Question:

You are given an array of k linked-lists lists, each linked-list is sorted in ascending order.
Merge all the linked-lists into one sorted linked-list and return it.

How arrays are passed to function | Basic and Important

Introduction:

Backtracking algorithm

Introduction:

287. Find the Duplicate Number

Question:

Given an array of integers nums containing n + 1 integers where each integer is in the range [1, n] inclusive.

There is only one repeated number in nums, return this repeated number.

Basic programming - Selection Sort

Approach:

Declare two variables, i likes the end pointer of sorted vector and j likes the scanning pointer.