Merge branch 'DaleStudy:main' into main

Author: Lustellz

contains-duplicate/DaleSeo.rs

@@ -0,0 +1,10 @@
+use std::collections::HashSet;
+
+// TC: O(n)
+// SC: O(n)
+impl Solution {
+    pub fn contains_duplicate(nums: Vec<i32>) -> bool {
+        let mut set = HashSet::new();
+        !nums.into_iter().all(|num| set.insert(num))
+    }
+}

contains-duplicate/Grit03.js

@@ -0,0 +1,22 @@
+/**
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var containsDuplicate = function (nums) {
+  const countMap = new Map();
+
+  for (let i = 0; i < nums.length; i++) {
+    const key = nums[i];
+    if (countMap.has(key)) {
+      const value = countMap.get(key);
+      if (value === 1) {
+        return true;
+      }
+      countMap.set(key, value + 1);
+    } else {
+      countMap.set(key, 1);
+    }
+  }
+
+  return false;
+};

contains-duplicate/SamTheKorean.go

@@ -0,0 +1,17 @@
+// TC : O(n) : it iterates for the length of nums
+// SC : O(n) : hashmap is created with the size of nums
+
+func containsDuplicate(nums []int) bool {
+    hashmap := make(map[int]bool)
+
+    for i:=0;i<len(nums);i++ {
+        if hashmap[nums[i]] {
+            return true
+        }
+
+        hashmap[nums[i]] = true
+    }
+
+    return false
+}
+

contains-duplicate/bskkimm.py

@@ -0,0 +1,24 @@
+from collections import defaultdict
+class Solution(object):
+    def containsDuplicate(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: bool
+        """
+        # [1,2,3,1]
+
+        # [1,1,1,3,3,4,3,2,4,2]
+
+        # add element to a dict
+        # if a same value appears, then return True
+        # if a for loop ends without disruption, return False
+
+        dict = defaultdict(bool)
+
+        for num in nums:
+            if dict[num]:
+                return True
+            else:
+                dict[num] = True
+
+        return False

contains-duplicate/chordpli.py

@@ -0,0 +1,12 @@
+from typing import List
+
+class Solution:
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        dic = {}
+
+        for num in nums:
+            if dic.get(num):
+                return True
+            dic[num] = 1
+
+        return False

contains-duplicate/devyejin.py

@@ -0,0 +1,4 @@
+class Solution(object):
+    def containsDuplicate(self, nums):
+        return len(nums) != len(set(nums))
+

contains-duplicate/do-heewan.py

@@ -0,0 +1,8 @@
+class Solution:
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        sets = set(nums)
+
+        if len(nums) != len(sets):
+            return True
+        return False
+

contains-duplicate/hj4645.py

@@ -0,0 +1,11 @@
+class Solution:
+    # 리스트 안에 동일한 숫자가 2개 이상 존재하면 true를 반환해야 하는 문제
+    # Set으로 변환 시 중복이 제거되므로 List와 Set의 크기를 비교해 답을 구할 수 있음
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        return len(nums) != len(set(nums))
+
+    # Time Complexity
+    # - set(nums) → O(n)
+    # - len(nums), len(set(nums)) → O(1)
+    # - Total: O(n) (n = number of list elements)
+

contains-duplicate/hoyeongkwak.java

@@ -0,0 +1,16 @@
+/*
+time complexity : O(n)
+space complexity : O(n)
+*/
+class Solution {
+    public boolean containsDuplicate(int[] nums) {
+        HashSet<Integer> uniqueNums = new HashSet<Integer>();
+
+        for (int num:nums) {
+            if (!uniqueNums.add(num)) {
+                return true;
+            }
+        }
+        return false;
+    }
+}

contains-duplicate/hyer0705.ts

@@ -0,0 +1,3 @@
+function containsDuplicate(nums: number[]): boolean {
+  return new Set<number>(nums).size !== nums.length;
+}