leetcode -- Palindrome Partitioning

 

谋事在人，成事在天

 

[问题描述]

 

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"]
  ]

 

[解题思路]

动态规划，dp[i][j] = s[i]==s[j]&&(j-i<2||dp[i+1][j-1])

 

vector<vector<string>> Solution::partition(string s){
    const int len = s.length();
    bool dp[len][len];
    fill_n(&dp[0][0], len*len, false);
    for (int i = len-1; i >=0; i --){
        for (int j = i; j < len; j++){
            dp[i][j] = s[i]==s[j]&&(j-i<2||dp[i+1][j-1]);
        }
    }
    vector<vector<string>> ans[len];
    for (int i = len-1; i>=0; i--){
        for (int j = i; j < len; j++){
            if (dp[i][j] == 1){
                const string tmp = s.substr(i, j-i+1);
                if (j + 1 >= len){
                    ans[i].push_back(vector<string> {tmp});
                }
                else{
                    for (auto k : ans[j + 1]){
                        k.insert(k.begin(), tmp);
                        ans[i].push_back(k);
                    }
                }
            }
        }
    }
    return ans[0];
}