palindrome partitioning

Author: zgpeace

code/LeetCode/src/backtracking/PalindromePartitioning.java

@@ -0,0 +1,56 @@
+package backtracking;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+// https://leetcode.com/problems/palindrome-partitioning/
+public class PalindromePartitioning {
+
+  public static void main(String[] args) {
+    String s = "aab";
+    PalindromePartitioning obj = new PalindromePartitioning();
+    List<List<String>> resultList = obj.partition(s);
+    System.out.println(Arrays.toString(resultList.toArray()));
+  }
+
+  public List<List<String>> partition(String s) {
+    List<List<String>> resultList = new ArrayList<List<String>>();
+    // dfs
+    dfs(s, 0, resultList, new ArrayList<String>());
+
+    return resultList;
+  }
+
+  private void dfs(String s, int start, List<List<String>> resultList, List<String> list) {
+    // exit
+    if (start >= s.length()) {
+      resultList.add(new ArrayList<String>(list));
+      return;
+    }
+
+    // for
+    for (int i = start; i < s.length(); i++) {
+
+      // isPalindrome
+      if (isPal(s, start, i)) {
+        // add
+        list.add(s.substring(start, i + 1));
+        dfs(s, i + 1, resultList, list);
+
+        // not add
+        list.remove(list.size() - 1);
+      }
+    }
+  }
+
+  private boolean isPal(String s, int l, int r) {
+    while (l < r) {
+      if (s.charAt(l++) != s.charAt(r--)) {
+        return false;
+      }
+    }
+
+    return true;
+  }
+}