Java-coding Problems Pdf Github

If I had to pick a single starting point today, it would be "TheAlgorithms/Java" on GitHub. It is not a problem set per se, but a massive collection of standard algorithms. The "problem" is figuring out when to use each one. Pair this with any generic "Coding Problems" PDF, and you have a full curriculum.

// Problematic code
String str = null;
System.out.println(str.length());
// Solution
String str = null;
if (str != null) 
    System.out.println(str.length());

# Install pandoc + a LaTeX engine (e.g., TinyTeX)
pandoc docs/*.md -o pdf/java-coding-problems.pdf \
  --toc \
  --pdf-engine=xelatex \
  -V geometry:margin=1in \
  -V mainfont="DejaVuSans"

Note: Always check the repo’s last update and license before using.

Problem: Two Sum
Given an array of integers nums and an integer target, return indices of the two numbers that add up to target. java-coding problems pdf github

Example
Input: nums = [2,7,11,15], target = 9
Output: [0,1]

Java Solution (HashMap – O(n) time, O(n) space) If I had to pick a single starting

public int[] twoSum(int[] nums, int target) 
    Map<Integer, Integer> map = new HashMap<>();
    for (int i = 0; i < nums.length; i++) 
        int complement = target - nums[i];
        if (map.containsKey(complement)) 
            return new int[]  map.get(complement), i ;
map.put(nums[i], i);
throw new IllegalArgumentException("No solution");

📄 Full PDF includes – 10+ test cases, edge handling (duplicates, negative numbers), and follow-up: what if array is sorted?

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Before diving into specific links, it's essential to understand why GitHub has become the preferred source over traditional websites like LeetCode or HackerRank for many developers. # Install pandoc + a LaTeX engine (e

After digging through hundreds of repos and Stack Overflow threads, here are the gold standards. I highly recommend searching for these titles followed by "pdf github" to find the latest community uploads or official repos.