[LeetCode] Palindrome Partitioning

Palindrome Partitioning

 

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"]
  ]

我居然是先做了II题，呵呵，一样的，有了上一题的dp数组来帮助判断某一个子串是否是回文了之后，我们回溯一下构造解就好了。

class Solution {
public:
    vector<vector<string>> partition(string s) {
        // Note: The Solution object is instantiated only once and is reused by each test case.
        int n=s.length();
		vector<vector<bool> > dp(n+1,vector<bool>(n,true));
		for(int len=2;len<=n;len++)
		{
			for(int start=0;start<=n-len;start++)
			{
				dp[len][start]=s[start]==s[len+start-1]&&dp[len-2][start+1];
			}
		}
		vector<vector<string> > ret;
		vector<string> part;
		solve(0,s,part,ret,dp);
		return ret;
    }
	void solve(int k,string& s,vector<string>& part,vector<vector<string> > & ret,vector<vector<bool> >& dp)
	{
		if(k>=s.length())
		{
			ret.push_back(part);
			return;
		}
		string cur;
		for(int i=k;i<s.length();i++)
		{
			cur.push_back(s[i]);
			if(dp[i-k+1][k])
			{
				part.push_back(cur);
				solve(i+1,s,part,ret,dp);
				part.pop_back();
			}
		}
	}
};