Back tracking

src/main/java/com/thealgorithm/backtracking/PalindromePartitioning.java

@@ -0,0 +1,57 @@
+package com.thealgorithm.backtracking;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * @author: Subham Santra
+ * @implNote
+ *     <p>This is a pure back-tracking approach This problem can be solved using dynamic programming
+ *     also, I will add DP code in DP section</p>
+ */
+public class PalindromePartitioning {
+
+  Boolean[][] memo;
+
+  public List<List<String>> partition(String s) {
+    memo = new Boolean[s.length()][s.length()];
+    List<List<String>> possiblePalindromes = new ArrayList<>();
+    partition(s, 0, new ArrayList<>(), possiblePalindromes);
+    return possiblePalindromes;
+  }
+
+  void partition(String s, int lo, List<String> current, List<List<String>> possiblePalindromes) {
+    if (lo == s.length()) {
+      possiblePalindromes.addFirst(new ArrayList<>(current));
+      return;
+    }
+
+    for (int p = lo; p < s.length(); ++p) {
+      if (isPalindrome(s, lo, p)) {
+        current.addLast(s.substring(lo, p + 1));
+        partition(s, p + 1, current, possiblePalindromes);
+        current.removeLast();
+      }
+    }
+  }
+
+  boolean isPalindrome(String s, int l, int h) {
+    if (memo[l][h] == null) {
+      for (int i = l, j = h; i <= j; ++i, --j) {
+        if (s.charAt(i) != s.charAt(j)) {
+          return memo[l][h] = false;
+        }
+      }
+      return memo[l][h] = true;
+    }
+    return memo[l][h];
+  }
+
+  public static void main(String[] args) {
+    System.out.println(new PalindromePartitioning().partition("baab"));
+    System.out.println(new PalindromePartitioning().partition("A"));
+    System.out.println(new PalindromePartitioning().partition("aab"));
+    System.out.println(new PalindromePartitioning().partition(""));
+    System.out.println(new PalindromePartitioning().partition("aababbababbabbabba"));
+  }
+}