Problem

Given a string s, partition s such that every substring of the partition is a palindrome. Return all possible palindrome partitioning of s.

A palindrome string is a string that reads the same backward as forward.

Constraints:

• 1 <= s.length <= 16
• s contains only lowercase English letters.

Example1

Input: s = “aab”
Output: [[“a”,“a”,“b”],[“aa”,“b”]]

Example2

Input: s = “a”
Output: [[“a”]]

Solution

class Solution {
public:
    vector<vector<bool>> f;
    vector<vector<string>> ans;
    vector<string> path;

    vector<vector<string>> partition(string s) {
        int n = s.size();
        f = vector<vector<bool>>(n, vector<bool>(n));
        for (int j = 0; j < n; j ++ )
            for (int i = 0; i <= j; i ++ )
                if (i == j) f[i][j] = true;
                else if (s[i] == s[j]) {
                        cout<<i<<" "<<j<<endl;
                    if (i + 1 > j - 1 || f[i + 1][j - 1]) f[i][j] = true;
                }
        
        dfs(s, 0);
        return ans;
    }

    void dfs(string& s, int u) {
        if (u == s.size()) ans.push_back(path);
        else {
            for (int i = u; i < s.size(); i ++ )
                if (f[u][i]) {
                    path.push_back(s.substr(u, i - u + 1));
                    dfs(s, i + 1);
                    path.pop_back();
                }
        }
    }
};