Given a string s, partition s such that every substring of the partition is a palindrome.
Return all possible palindrome partitioning of s.
For example, given s = "aab",
Return
[
["aa","b"],
["a","a","b"]
]
先DP找出所有的回文字符串,存储在二维数组f中,然后深搜,使用递归增量法
public class Solution {
boolean f[][];
List
> res = new ArrayList<>();
public List
> partition(String s) { f = new boolean[s.length()][s.length()]; for (int i = 0; i < s.length(); i++) { f[i][i] = true; } int maxLen = 1; for (int i = 0; i < s.length() - 1; i++) { if (s.charAt(i) == s.charAt(i + 1)) { f[i][i + 1] = true; maxLen = 2; } } for (int len = 3; len <= s.length(); len++) { boolean in = false; for (int i = 0; i < s.length() - len + 1; i++) { if (s.charAt(i) == s.charAt(i + len-1) && f[i + 1][i + len - 2]) { f[i][i + len-1] = true; in = true; } } if (in) { maxLen = len; } } partition(s, maxLen, 0, new ArrayList
()); return res; } private void partition(String s, int maxLen, int start, List
path) { if (start >= s.length()) { List
lin = new ArrayList<>(path); res.add(lin); return; } for (int len = 1; len <= maxLen; len++) { if (start + len - 1 > s.length() - 1) break; if (f[start][start + len - 1]) { path.add(s.substring(start, start + len)); partition(s, maxLen, start + len, path); path.remove(path.size() - 1); } } } }