System.arraycopy() vs. Arrays.copyOf() in Java
If we want to copy an array, we can use either System.arraycopy() or Arrays.copyOf(). In this post, I use a simple example to demonstrate the difference between the two. 1. Simple Code Examples...
View ArticlePrint an Array in Java
This post summarizes 5 different ways of printing an array in Java. 5 Different Ways of Printing an Array Arrays.toString(arr) for(int n: arr) System.out.println(n+", "); for (int i = 0; i <...
View ArticleLeetCode – Counting Bits (Java)
Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1’s in their binary representation and return them as an array. Example: For num = 5...
View ArticleLeetCode – House Robber III (Java)
The houses form a binary tree. If the root is robbed, its left and right can not be robbed. Analysis Traverse down the tree recursively. We can use an array to keep 2 values: the maximum money when a...
View ArticleLeetCode – Self Crossing (Java)
Analysis This problem can be easily solved if the three self crossing cases are summarized well. Here are the three self crossing cases. There are no other self crossing situations based on the...
View ArticleLeetCode – Reconstruct Itinerary (Java)
Given a list of airline tickets represented by pairs of departure and arrival airports [from, to], reconstruct the itinerary in order. All of the tickets belong to a man who departs from JFK. Thus, the...
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