Day39.java

/*Array Subset
Given two arrays a[] and b[], your task is to determine whether b[] is a subset of a[].

Examples:

Input: a[] = [11, 7, 1, 13, 21, 3, 7, 3], b[] = [11, 3, 7, 1, 7]
Output: true
Explanation: b[] is a subset of a[]
Input: a[] = [1, 2, 3, 4, 4, 5, 6], b[] = [1, 2, 4]
Output: true
Explanation: b[] is a subset of a[]
Input: a[] = [10, 5, 2, 23, 19], b[] = [19, 5, 3]
Output: false
Explanation: b[] is not a subset of a[] */
/* import java.util.*;

class Solution {
    public boolean isSubset(int a[], int b[]) {
        HashMap<Integer, Integer> map = new HashMap<>();

        // Count frequency of elements in a[]
        for (int num : a) {
            map.put(num, map.getOrDefault(num, 0) + 1);
        }

        // Check elements of b[]
        for (int num : b) {
            if (!map.containsKey(num) || map.get(num) == 0) {
                return false;
            }
            map.put(num, map.get(num) - 1);
        }

        return true;
    }
}
*/
/*⏱ Complexity

Time: O(n + m)

Space: O(n) */