[LEET-3471] add 3471

Author: fishercoder1534

paginated_contents/algorithms/4th_thousand/README.md

@@ -1,5 +1,6 @@
 | #    | Title                                                                                                                                                               | Solutions                                                                                                                         | Video                                                                         | Difficulty | Tag                                                                  
 |------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------|------------|----------------------------------------------------------------------
+| 3471 | [Find the Largest Almost Missing Integer](https://leetcode.com/problems/find-the-largest-almost-missing-integer/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3471.java) |                                                                               | Easy       |
 | 3396 | [Minimum Number of Operations to Make Elements in Array Distinct](https://leetcode.com/problems/minimum-number-of-operations-to-make-elements-in-array-distinct/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3396.java) |                                                                               | Easy       |
 | 3392 | [Count Subarrays of Length Three With a Condition](https://leetcode.com/problems/count-subarrays-of-length-three-with-a-condition/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3392.java) |                                                                               | Easy       |
 | 3386 | [Button with Longest Push Time](https://leetcode.com/problems/button-with-longest-push-time/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3386.java) |                                                                               | Easy       |

src/main/java/com/fishercoder/solutions/fourththousand/_3471.java

@@ -0,0 +1,31 @@
+package com.fishercoder.solutions.fourththousand;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.TreeMap;
+
+public class _3471 {
+    public static class Solution1 {
+        public int largestInteger(int[] nums, int k) {
+            TreeMap<Integer, Integer> map = new TreeMap<>();
+            for (int num : nums) {
+                map.put(num, 0);
+            }
+            for (int i = 0; i <= nums.length - k; i++) {
+                Set<Integer> set = new HashSet<>();
+                for (int j = i; j < i + k; j++) {
+                    if (set.add(nums[j])) {
+                        map.put(nums[j], map.getOrDefault(nums[j], 0) + 1);
+                    }
+                }
+            }
+            int ans = -1;
+            for (int key : map.keySet()) {
+                if (map.get(key) == 1) {
+                    ans = key;
+                }
+            }
+            return ans;
+        }
+    }
+}

src/test/java/com/fishercoder/fourththousand/_3471Test.java

@@ -0,0 +1,26 @@
+package com.fishercoder.fourththousand;
+
+import com.fishercoder.solutions.fourththousand._3471;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class _3471Test {
+    private _3471.Solution1 solution1;
+
+    @BeforeEach
+    public void setup() {
+        solution1 = new _3471.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        assertEquals(7, solution1.largestInteger(new int[]{3, 9, 2, 1, 7}, 3));
+    }
+
+    @Test
+    public void test2() {
+        assertEquals(0, solution1.largestInteger(new int[]{0, 0}, 2));
+    }
+}