Algorithms – Part 4: Longest Sub-integers Without Repeating Integers (Brute Force)

Question:

Given an array of integers, find the length of the longest subarray with distinct elements.

Solution:

import java.util.Set;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;

public class LongestSubIntegeres {
    int x = 0;

    public int lengthOfLongestDistinctSubarray(int[] nums) {
        int n = nums.length;
        int ans = 0;
        

        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j < n; j++) {
                if (allUnique(nums,i,j)) ans = Math.max(ans, j - i);
            }
        }
        return ans;
    }

    public boolean allUnique(int[] n, int start, int end) {
        // Set<Character> set = new HashSet<>();
        List<Integer> intList = new ArrayList<Integer>(n.length);

        for (int i = start; i < end; i++) {
            // Character ch = n.charAt(i);
            x = n[i];
            if (intList.contains(x)) return false;
            intList.add(x);
            // System.out.println(intList);
        }
        return true;
    }
    
    public static void main(String[] args) {
        int[] nums = {1, 2, 3, 4, 5, 2, 3, 6, 7};
        LongestSubIntegeres longestSubarray = new LongestSubIntegeres();
        int answer = longestSubarray.lengthOfLongestDistinctSubarray(nums);
        System.out.println("The answer is: " + answer);
    }
}