[Leo] 12th Week solutions (2,3)

Author: leokim0922

longest-common-subsequence/Leo.py

@@ -0,0 +1,15 @@
+class Solution:
+    def longestCommonSubsequence(self, text1: str, text2: str) -> int:
+        dp = [0] * (len(text2) + 1)
+
+        for i in range(len(text1)):
+            prev_row = dp[:]
+            for j in range(len(text2)):
+                if text1[i] == text2[j]:
+                    dp[j + 1] = prev_row[j] + 1
+                else:
+                    dp[j + 1] = max(dp[j], prev_row[j + 1])
+
+        return dp[-1]
+
+        ## TC: O(mn), SC: O(n)

unique-paths/Leo.py

@@ -0,0 +1,13 @@
+class Solution:
+    def uniquePaths(self, m: int, n: int) -> int:
+        dp = [1] * n
+
+        for _ in range(1, m):
+            for i in range(1, n):
+                dp[i] += dp[i - 1]
+
+        return dp[-1]
+        ## TC: O(mn), SC: O(n)
+
+        ## return math.comb(m + n - 2, m - 1)
+        ## TC: O(1) whatever constant, SC: O(1)