Welcome to the world of coding problems! In this lesson, we will be exploring various techniques and strategies for solving coding problems.
As a senior engineer with intermediate knowledge of Java and Python, you are already familiar with the fundamentals of programming. However, coding problems often require a different approach and level of thinking.
Whether you are preparing for coding interviews or simply looking to improve your problem-solving skills, this lesson will provide you with valuable insights and strategies.
Throughout this course, we will cover a wide range of topics, including arrays, strings, linked lists, trees, sorting and searching, dynamic programming, graphs, system design, object-oriented design, and behavioral interview questions.
To start things off, let's write a simple Java program to find the two numbers in an array that add up to a target sum:
1import java.util.Arrays;
2
3public class Main {
4
5 public static void main(String[] args) {
6 int[] nums = {1, 2, 3, 4, 5};
7 int target = 9;
8 int[] result = twoSum(nums, target);
9 System.out.println(Arrays.toString(result));
10 }
11
12 public static int[] twoSum(int[] nums, int target) {
13 int[] result = new int[2];
14 // Replace with your Java logic here
15 return result;
16 }
17}```
18
19In this program, we are given an array `nums` and a target sum. Our task is to find the two numbers in the array that add up to the target sum and return their indices.
20
21To solve this problem, we can use the two-pointer technique. We can start with two pointers, one at the beginning of the array and one at the end. We can then move the pointers towards each other until we find a pair that adds up to the target sum.
22
23You can replace the comment `Replace with your Java logic here` with your own implementation of the `twoSum` method to solve the problem.
24
25Try running the program and see if you can find the two numbers that add up to the target sum!xxxxxxxxxx```javaimport java.util.Arrays;public class Main { public static void main(String[] args) { // Replace with your Java logic here int[] nums = {1, 2, 3, 4, 5}; int target = 9; int[] result = twoSum(nums, target); System.out.println(Arrays.toString(result)); } public static int[] twoSum(int[] nums, int target) { int[] result = new int[2]; // Replace with your Java logic here return result; }}