added another problem

Author: Chiefpatwal

src/main/java/com/thealgorithms/slidingwindow/MinimumConsecutiveCards.java

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+package com.thealgorithms.slidingwindow;
+
+import java.util.HashMap;
+
+/**
+ * The MinimumConsecutiveCards algorithm finds the minimum number of consecutive cards
+ * that need to be picked up to get a pair of the same card.
+ *
+ * <p>
+ * Worst-case performance O(n)
+ * Best-case performance O(n)
+ * Average performance O(n)
+ * Worst-case space complexity O(n)
+ *
+ * @author  (https://github.com/Chiefpatwal)
+ */
+public final class MinimumConsecutiveCards {
+
+    // Prevent instantiation
+    private MinimumConsecutiveCards() {
+    }
+
+    /**
+     * This method finds the minimum number of consecutive cards needed to be picked up
+     * to get a pair of the same card.
+     *
+     * @param cards an array of integers representing card numbers
+     * @return the minimum number of consecutive cards to pick up, or -1 if no pairs exist
+     */
+    public static int minimumCardPickup(int[] cards) {
+        HashMap<Integer, Integer> cardIndexMap = new HashMap<>();
+        int minLength = Integer.MAX_VALUE;
+
+        for (int i = 0; i < cards.length; i++) {
+            if (cardIndexMap.containsKey(cards[i])) {
+                int prevIndex = cardIndexMap.get(cards[i]);
+                minLength = Math.min(minLength, i - prevIndex + 1);
+            }
+            cardIndexMap.put(cards[i], i);
+        }
+
+        return minLength == Integer.MAX_VALUE ? -1 : minLength;
+    }
+}

src/test/java/com/thealgorithms/slidingwindow/MinimumConsecutiveCardsTest.java

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+package com.thealgorithms.slidingwindow;
+
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/**
+ * Unit tests for the MinimumConsecutiveCards class.
+ *
+ * @author (https://github.com/Chiefpatwal)
+ */
+public class MinimumConsecutiveCardsTest {
+
+    @Test
+    public void testMinimumCardPickup() {
+        // Test cases for the minimumCardPickup method
+        assertEquals(2, MinimumConsecutiveCards.minimumCardPickup(new int[]{1, 2, 3, 2, 4, 1}));
+        assertEquals(-1, MinimumConsecutiveCards.minimumCardPickup(new int[]{1, 2, 3, 4, 5}));
+        assertEquals(2, MinimumConsecutiveCards.minimumCardPickup(new int[]{1, 1, 1, 1}));
+        assertEquals(2, MinimumConsecutiveCards.minimumCardPickup(new int[]{2, 2, 3, 4, 5}));
+    }
+}