2260. Minimum Consecutive Cards to Pick Up

Problem

You are given an integer array cards where cards[i] represents the value of the ith card. A pair of cards are matching if the cards have the same value.

Return** the minimum number of consecutive cards you have to pick up to have a pair of matching cards among the picked cards.** If it is impossible to have matching cards, return -1.

  Example 1:

Input: cards = [3,4,2,3,4,7]
Output: 4
Explanation: We can pick up the cards [3,4,2,3] which contain a matching pair of cards with value 3. Note that picking up the cards [4,2,3,4] is also optimal.

Example 2:

Input: cards = [1,0,5,3]
Output: -1
Explanation: There is no way to pick up a set of consecutive cards that contain a pair of matching cards.

  Constraints:

• 1 <= cards.length <= 10^5

• 0 <= cards[i] <= 10^6

Solution (Java)

class Solution {
    public int minimumCardPickup(int[] cards) {
        int mindiff = Integer.MAX_VALUE;
        Map<Integer, Integer> map = new HashMap<>();
        int n = cards.length;
        for (int i = 0; i < n; i++) {
            if (map.containsKey(cards[i])) {
                int j = map.get(cards[i]);
                mindiff = Math.min(mindiff, i - j + 1);
            }
            map.put(cards[i], i);
        }
        if (mindiff == Integer.MAX_VALUE) {
            return -1;
        }
        return mindiff;
    }
}

Explain:

nope.

Complexity:

• Time complexity : O(n).
• Space complexity : O(n).