[jeongyunjae] WEEK 01 solutions

contains-duplicate/jeongyunjae.py

@@ -0,0 +1,3 @@
+class Solution:
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        return len(list(set(nums))) != len(nums)

house-robber/jeongyunjae.py

@@ -0,0 +1,18 @@
+class Solution:
+    def rob(self, nums: List[int]) -> int:
+        result = list(nums)
+
+        for i, data in enumerate(result):
+            if i <= 1:
+                continue
+
+            stolen_money = result[i]
+            before_house_money = result[i-1]
+
+            for j in range(i-1):
+                if result[i] + result[j] > stolen_money:
+                    stolen_money = result[i] + result[j]
+
+            result[i] = max(before_house_money, stolen_money)    
+
+        return max(result)

longest-consecutive-sequence/jeongyunjae.py

@@ -0,0 +1,16 @@
+class Solution:
+    def longestConsecutive(self, nums: List[int]) -> int:
+        if len(nums) <= 1:
+            return len(nums)
+
+        result = [1] * len(nums)
+
+        # 중복 제거 후 정렬
+        nums = sorted(list(set(nums)))
+
+        # 연속된 숫자 찾기
+        for i in range(1, len(nums)):
+            if nums[i] - 1 == nums[i-1]:
+                result[i] = result[i-1] + 1
+
+        return max(result)

top-k-frequent-elements/jeongyunjae.py

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+class Solution:
+    def topKFrequent(self, nums: List[int], k: int) -> List[int]:
+        my_dict = {}
+        result = []
+        temp_list = []
+
+        # 딕셔너리 생성
+        for data in nums:
+            if data not in my_dict.keys():
+                my_dict[data] = 0
+            my_dict[data] = my_dict[data] + 1 
+
+        # 딕셔너리를 리스트로 변환
+        for data in my_dict.keys():
+            temp_list.append([data, my_dict[data]])
+
+        # 빈도수를 기준으로 정렬
+        temp_list.sort(key=lambda a: a[1],reverse=True)
+
+        # 상위 k개 요소 추출
+        for i in range(k):
+            result.append(temp_list[i][0])
+
+        return result

two-sum/jeongyunjae.py

@@ -0,0 +1,11 @@
+class Solution:
+
+    def twoSum(self, nums: List[int], target: int) -> List[int]:
+        my_dict = {}
+
+        for i, data in enumerate(nums):
+            remaining = target - data
+            if remaining not in my_dict:
+                my_dict[data] = i
+            else:
+                return [my_dict[remaining], i]