131. Palindrome Partitioning

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131. Palindrome Partitioning

Description

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

Example 1:

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

Example 2:

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Input: s = "a"
Output: [["a"]]

Constraints:

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

Hints/Notes

Solution

Language: C++

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class Solution {
public:
    vector<string> path;
    vector<vector<string>> res;

    vector<vector<string>> partition(string s) {
        dfs(0, s);
        return res;
    }

    void dfs(int index, string& s) {
        if (index == s.size()) {
            res.push_back(path);
            return;
        }

        for (int i = index + 1; i <= s.size(); i++) {
            if (isPalindrome(s, index, i - 1)) {
                path.push_back(s.substr(index, i - index));
                dfs(i, s);
                path.pop_back();
            }
        }
    }

    bool isPalindrome(string& s, int l, int r) {
        if (l >= r) {
            return true;
        }
        if (dp[l][r] != -1) {
            return dp[l][r];
        }
        int& res = dp[l][r];
        if (s[l] != s[r]) {
            res = 0;
            return res;
        }
        res = isPalindrome(s, l + 1, r - 1);
        return res;
    }
};