Bitonic

LongestBitonicSequence.py

@@ -0,0 +1,41 @@
+answer = []
+def index_ceiling(arr,T, left,right, key):
+   while (right - left > 1):
+      mid = left + (right - left) // 2;
+      if (arr[T[mid]] >= key):
+         right = mid
+      else:
+         left = mid
+   return right
+def long_inc_seq(A):
+   n = len(A)
+   tails_idx = [0]*(n)
+   prev_idx = [-1]*(n)
+   length = 1
+   for i in range(1, n):
+      if (A[i] < A[tails_idx[0]]):
+         tails_idx[0] = i
+      elif (A[i] > A[tails_idx[length - 1]]):
+         prev_idx[i] = tails_idx[length - 1]
+         tails_idx[length] = i
+         length += 1
+      else:
+         pos = index_ceiling(A, tails_idx, -1, length - 1, A[i])
+         prev_idx[i] = tails_idx[pos - 1]
+         tails_idx[pos] = i
+   i = tails_idx[length - 1]
+   while(i >= 0):
+      answer.append(A[i])
+      i = prev_idx[i]
+def long_bitonic(A,B):
+   n1 = len(A)
+   n2 = len(B)
+   global answer
+   long_inc_seq(A)
+   answer = answer[::-1]
+   B = B[::-1]
+   long_inc_seq(B)
+A = [2, 6, 3, 5, 4, 6]
+B = [9, 7, 5, 8, 4, 3]
+long_bitonic(A,B)
+print(answer)

LongestPalindromicSubsequence.py

@@ -0,0 +1,16 @@
+def longestPalindromeSubseq(self, s: str) -> int:
+        n = len(s)
+        dp = [[0]*(n) for _ in range(n) ]
+
+        for i in range(n):
+            dp[i][i] = 1
+
+
+        for i in range(n-1, -1, -1):
+            for j in range(i+1, n):                    
+                if s[i]==s[j]:
+                    dp[i][j] = dp[i+1][j-1]+2
+                else:
+                    dp[i][j] = max(dp[i][j-1], dp[i+1][j])
+
+        return dp[0][-1]