2338. Minimum Consecutive Cards To Pick Up¶

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2338. Minimum Consecutive Cards to Pick Up

Medium

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 <= 105
• 0 <= cards[i] <= 106

Solution¶

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

Complexity Analysis¶

• Time Complexity: O(?)
• Space Complexity: O(?)

Approach¶

Detailed explanation of the approach will be added here