1213. Intersection of Three Sorted Arrays

Given three integer arrays arr1, arr2 and arr3 sorted in strictly increasing order, return a sorted array of only the integers that appeared in all three arrays.

Example 1:

Input: arr1 = [1,2,3,4,5], arr2 = [1,2,5,7,9], arr3 = [1,3,4,5,8]
Output: [1,5]
Explanation: Only 1 and 5 appeared in the three arrays.

Example 2:

Input: arr1 = [197,418,523,876,1356], arr2 = [501,880,1593,1710,1870], arr3 = [521,682,1337,1395,1764]
Output: []

class Solution {
    public List<Integer> arraysIntersection(int[] arr1, int[] arr2, int[] arr3) {
        int a = 0, b = 0, c = 0;
        List<Integer> res = new ArrayList<>();
        while (a < arr1.length && b < arr2.length && c < arr3.length) {
            int min = Math.min(arr1[a], Math.min(arr2[b], arr3[c]));
            if (arr1[a] == min && arr2[b] == min && arr3[c] == min) res.add(min);
            if (arr1[a] == min) a++;
            if (arr2[b] == min) b++;
            if (arr3[c] == min) c++;
        }
        return res;
    }
}