feat: 每日一题参考答案2019-06-20

daily/answers/594.longest-harmonious-subsequence.js

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+/*
+ * @lc app=leetcode id=594 lang=javascript
+ *
+ * [594] Longest Harmonious Subsequence
+ */
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var findLHS = function(nums) {
+  // Input: [1,3,2,2,5,2,3,7]
+  // Output: 5
+  // Explanation: The longest harmonious subsequence is [3,2,2,2,3].
+  if (nums.length === 0) return 0;
+  const counts = {};
+  let res = 0;
+
+  for (let i = 0; i < nums.length; i++) {
+    if (!counts[nums[i]]) {
+      counts[nums[i]] = 1;
+    } else {  
+      counts[nums[i]] += 1;
+    }
+  }
+
+  for (let i = 0; i < nums.length; i++) {
+    if (counts[nums[i] + 1]) {
+      res = Math.max(res, counts[nums[i]] + counts[nums[i] + 1]);
+    }
+  }
+
+  return res;
+};