8

Author: rimijoker

Algoexpert/Very Hard/Palindrome Partitioning Min Cuts.py

@@ -0,0 +1,55 @@
+# O(N^3) time | O(N^2) space
+
+
+def palindromePartitionMinCuts(string):
+    palindromes = [[False for _ in string] for _ in string]
+    for i in range(len(string)):
+        for j in range(i, len(string)):
+            palindromes[i][j] = isPalindrome(string[i : j + 1])
+    cuts = [float("inf") for _ in string]
+    for i in range(len(string)):
+        if palindromes[0][i]:
+            cuts[i] = 0
+        else:
+            cuts = cuts[i - 1] + 1
+            for j in range(1, i):
+                if palindromes[j][i] and cuts[j - 1] + 1 < cuts[i]:
+                    cuts[i] = cuts[j - 1] + 1
+    return cuts[-1]
+
+
+def isPalindrome(string):
+    leftIdx = 0
+    rightIdx = len(string) - 1
+    while leftIdx < rightIdx:
+        if string[leftIdx] != string[rightIdx]:
+            return False
+        leftIdx += 1
+        rightIdx -= 1
+    return True
+
+
+# O(N^2) time | O(N^2) space
+
+
+def palindromePartitionMinCuts(string):
+    palindromes = [[False for _ in string] for _ in string]
+    for i in range(len(string)):
+        palindromes[i][i] = True
+    for length in range(2, len(string) + 1):
+        for i in range(0, len(string) - length + 1):
+            j = i + length - 1
+            if length == 2:
+                palindromes[i][j] = string[i] == string[j]
+            else:
+                palindromes[i][j] = string[i] == string[j] and palindromes[i + 1][j - 1]
+    cuts = [float("inf") for _ in string]
+    for i in range(len(string)):
+        if palindromes[0][i]:
+            cuts[i] = 0
+        else:
+            cuts = cuts[i - 1] + 1
+            for j in range(1, i):
+                if palindromes[j][i] and cuts[j - 1] + 1 < cuts[i]:
+                    cuts[i] = cuts[j - 1] + 1
+    return cuts[-1]