[환미니니] Week1 문제풀이

contains-duplicate/hwanminini.js

@@ -0,0 +1,10 @@
+// 시간복잡도: O(n)
+// 공간복잡도: O(n)
+
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var containsDuplicate = function(nums) {
+    return nums.length !== new Set(nums).size
+};

number-of-1-bits/hwanmini.js

@@ -0,0 +1,20 @@
+// 시간복잡도: O(log n)
+// 공간복잡도: O(log n)
+
+const replaceZeroToEmptyString = (str) => str.replaceAll('0','')
+
+
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var hammingWeight = function(n) {
+    const binaryNum = n.toString(2)
+    const replacedNumber = replaceZeroToEmptyString(binaryNum)
+    return replacedNumber.length
+};
+
+
+console.log(hammingWeight(11));
+console.log(hammingWeight(128));
+console.log(hammingWeight(2147483645));

top-k-frequent-elements/hwanmini.js

@@ -0,0 +1,23 @@
+// 시간복잡도: O(n log n)
+// 공간복잡도: O(n)
+
+/**
+ * @param {number[]} nums
+ * @param {number} k
+ * @return {number[]}
+ */
+var topKFrequent = function(nums, k) {
+    const map = new Map()
+
+    for (let i = 0; i < nums.length; i++) {
+        map.set(nums[i], (map.get(nums[i]) || 0) + 1);
+    }
+
+    const frequencyArr  = [...map]
+    const sortedArr = frequencyArr.toSorted((a,b) => b[1] - a[1])
+
+    return sortedArr.slice(0,k).map(([key,value]) => key);
+
+};
+
+console.log(topKFrequent([1,1,1,2,2,3],2))