solve problem Degree Of An Array

Author: P-ppc

README.md

@@ -92,6 +92,7 @@ All solutions will be accepted!
 |551|[Student Attendance Record I](https://leetcode-cn.com/problems/student-attendance-record-i/description/)|[java/py/js](./algorithms/StudentAttendanceRecordI)|Easy|
 |538|[Convert Bst To Greater Tree](https://leetcode-cn.com/problems/convert-bst-to-greater-tree/description/)|[java/py/js](./algorithms/ConvertBstToGreaterTree)|Easy|
 |235|[Lowest Common Ancestor Of A Binary Search Tree](https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-search-tree/description/)|[java/py/js](./algorithms/LowestCommonAncestorOfABinarySearchTree)|Easy|
+|697|[Degree Of An Array](https://leetcode-cn.com/problems/degree-of-an-array/description/)|[java/py/js](./algorithms/DegreeOfAnArray)|Easy|
 
 # Database
 |#|Title|Solution|Difficulty|

algorithms/DegreeOfAnArray/README.md

@@ -0,0 +1,2 @@
+# Degree Of An Array
+This problem is easy to solve by hashmap

algorithms/DegreeOfAnArray/Solution.java

@@ -0,0 +1,41 @@
+class Solution {
+    public int findShortestSubArray(int[] nums) {
+        Map<Integer, Map<String, Integer>> numsMap = new HashMap<Integer, Map<String, Integer>>();
+        List<Integer> mostNums = new ArrayList<Integer>();
+        int maxCount = 0;
+        int shortestLength = Integer.MAX_VALUE;
+        
+        for (int i = 0; i < nums.length; i++) {
+            int num = nums[i];
+            Map<String, Integer> map;
+            
+            if (numsMap.get(num) == null) {
+                map = new HashMap<String, Integer>();
+                map.put("start", i);
+                map.put("end", i);
+                map.put("count", 1);
+                numsMap.put(num, map);
+            } else {
+                map = numsMap.get(num);
+                map.put("end", i);
+                map.put("count", map.get("count") + 1);
+                numsMap.put(num, map);
+            }
+            
+            if (map.get("count") > maxCount) {
+                maxCount = map.get("count");
+                mostNums.clear();
+                mostNums.add(num);
+            } else if (map.get("count") == maxCount) {
+                mostNums.add(num);
+            }
+        }
+        
+        for (int num : mostNums) {
+            Map<String, Integer> map = numsMap.get(num);
+            shortestLength = Math.min(shortestLength, map.get("end") - map.get("start") + 1);
+        }
+        
+        return shortestLength;
+    }
+}

algorithms/DegreeOfAnArray/solution.js

@@ -0,0 +1,33 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var findShortestSubArray = function(nums) {
+    let numsMap = {},
+        mostNums = [],
+        maxCount = 0
+    
+    for (let i = 0; i < nums.length; i++) {
+        let num = nums[i]
+        
+        if (numsMap[num] === undefined) {
+            numsMap[num] = {
+                start: i,
+                end: i,
+                count: 1
+            }
+        } else {
+            numsMap[num].end = i
+            numsMap[num].count += 1
+        }
+        
+        if (numsMap[num].count > maxCount) {
+            maxCount = numsMap[num].count
+            mostNums = [num]
+        } else if (numsMap[num].count === maxCount) {
+            mostNums.push(num)
+        }
+    }
+    
+    return Math.min(...mostNums.map(num => numsMap[num].end - numsMap[num].start + 1))
+};

algorithms/DegreeOfAnArray/solution.py

@@ -0,0 +1,30 @@
+class Solution(object):
+    def findShortestSubArray(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: int
+        """
+        nums_map = {}
+        most_nums = []
+        max_count = 0
+        
+        for i in range(0, len(nums)):
+            num = nums[i]
+            if nums_map.get(num) == None:
+                nums_map[num] = {
+                    'start': i,
+                    'end': i,
+                    'count': 1
+                }
+            else:
+                nums_map[num]['end'] = i
+                nums_map[num]['count'] += 1
+            
+            if nums_map[num]['count'] > max_count:
+                max_count = nums_map[num]['count']
+                most_nums = [num]
+            elif nums_map[num]['count'] == max_count:
+                most_nums.append(num)
+        
+        return min([nums_map[num]['end'] - nums_map[num]['start'] + 1 for num in most_nums])
+