[jinah92] Week 1

contains-duplicate/jinah92.py

@@ -0,0 +1,10 @@
+class Solution:
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        keys = set()
+        for num in nums:
+            if num in keys:
+                return True
+            else:
+                keys.add(num)
+
+        return False

house-robber/jinah92.py

@@ -0,0 +1,16 @@
+class Solution:
+    def rob(self, nums: List[int]) -> int:
+        memo = {}
+
+        def getAmount(start: int) -> int:
+            if not start < len(nums):
+                memo[start] = 0
+            if start in memo:
+                return memo[start]
+
+            memo[start] = max(nums[start] + getAmount(start+2), getAmount(start+1))
+
+            return memo[start]
+
+        return getAmount(0)
+

longest-consecutive-sequence/jinah92.py

@@ -0,0 +1,18 @@
+class Solution:
+    def longestConsecutive(self, nums: List[int]) -> int:
+        result, last = 0, None
+        candidates = []
+
+        for num in sorted(set(nums)):
+            if last is None or last + 1 == num:
+                result += 1
+            else:
+                candidates.append(result)
+                result = 1
+            last = num
+
+        if result is not 0:
+            candidates.append(result)
+
+        return max(candidates) if len(candidates) > 0 else 0
+

top-k-frequent-elements/jinah92.py

@@ -0,0 +1,12 @@
+class Solution:
+    def topKFrequent(self, nums: List[int], k: int) -> List[int]:
+        counters = {}
+
+        for num in nums:
+            if counters.get(num):
+                counters[num] += 1
+            else:
+                counters[num] = 1
+
+        return [val[0] for val in sorted(counters.items(), key=lambda x: x[1], reverse=True)[:k]]
+

valid-palindrome/jinah92.py

@@ -0,0 +1,19 @@
+import re
+
+class Solution:
+    def isPalindrome(self, s: str) -> bool:
+        replaced_string = re.sub(r"[^a-zA-Z0-9]", "", s).lower()
+
+        if len(replaced_string) == 0:
+            return True
+
+        start, end = 0, len(replaced_string)-1
+
+        while start <= len(replaced_string) // 2:
+            if replaced_string[start] is not replaced_string[end]:
+                return False
+
+            start += 1
+            end -= 1
+
+        return True