add a solution for 697

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_697.java

@@ -1,10 +1,6 @@
 package com.fishercoder.solutions;
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 public class _697 {
     public static class Solution1 {
@@ -77,4 +73,33 @@ public int findShortestSubArray(int[] nums) {
             return result;
         }
     }
+
+    public static class Solution3 {
+        public int findShortestSubArray(int[] nums) {
+            Map<Integer, Integer> frequencyMap = new HashMap<>();
+            Map<Integer, List<Integer>> numberToIndicesMap = new HashMap<>();
+            for (int i = 0; i < nums.length; i++) {
+                frequencyMap.put(nums[i], frequencyMap.getOrDefault(nums[i], 0) + 1);
+                List<Integer> indices = numberToIndicesMap.getOrDefault(nums[i], new ArrayList<>());
+                indices.add(i);
+                numberToIndicesMap.put(nums[i], indices);
+            }
+            int degree = 0;
+            Set<Integer> numbersThatOccurTheMost = new HashSet<>();
+            for (Map.Entry<Integer, Integer> entry : frequencyMap.entrySet()) {
+                degree = Math.max(degree, entry.getValue());
+            }
+            for (Map.Entry<Integer, Integer> entry : frequencyMap.entrySet()) {
+                if (entry.getValue() == degree) {
+                    numbersThatOccurTheMost.add(entry.getKey());
+                }
+            }
+            int result = nums.length;
+            for (int num : numbersThatOccurTheMost) {
+                List<Integer> indices = numberToIndicesMap.get(num);
+                result = Math.min(result, indices.get(indices.size() - 1) - indices.get(0) + 1);
+            }
+            return result;
+        }
+    }
 }

src/test/java/com/fishercoder/_697Test.java

@@ -9,47 +9,54 @@
 public class _697Test {
     private static _697.Solution1 solution1;
     private static _697.Solution2 solution2;
+    private static _697.Solution3 solution3;
     private static int[] nums;
 
     @BeforeClass
     public static void setup() {
         solution1 = new _697.Solution1();
         solution2 = new _697.Solution2();
+        solution3 = new _697.Solution3();
     }
 
     @Test
     public void test1() {
         nums = new int[]{1};
         assertEquals(1, solution1.findShortestSubArray(nums));
         assertEquals(1, solution2.findShortestSubArray(nums));
+        assertEquals(1, solution3.findShortestSubArray(nums));
     }
 
     @Test
     public void test2() {
         nums = new int[]{1, 2, 2, 3, 1};
         assertEquals(2, solution1.findShortestSubArray(nums));
         assertEquals(2, solution2.findShortestSubArray(nums));
+        assertEquals(2, solution3.findShortestSubArray(nums));
     }
 
     @Test
     public void test3() {
         nums = new int[]{1, 2, 2, 3, 1, 1};
         assertEquals(6, solution1.findShortestSubArray(nums));
         assertEquals(6, solution2.findShortestSubArray(nums));
+        assertEquals(6, solution3.findShortestSubArray(nums));
     }
 
     @Test
     public void test4() {
         nums = new int[]{1, 2, 2, 3, 1, 1, 5};
         assertEquals(6, solution1.findShortestSubArray(nums));
         assertEquals(6, solution2.findShortestSubArray(nums));
+        assertEquals(6, solution3.findShortestSubArray(nums));
     }
 
     @Test
     public void test5() {
         nums = new int[]{1, 2, 2, 3, 1, 4, 2};
         assertEquals(6, solution1.findShortestSubArray(nums));
         assertEquals(6, solution2.findShortestSubArray(nums));
+        assertEquals(6, solution3.findShortestSubArray(nums));
     }
 
 }