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"]
]

速度较快的解法，回溯法：

class Solution {
public:
std::vector<std::vector<std::string> > partition(std::string s) {
len = s.size();
std::vector<std::vector<std::string> > res;
std::vector<std::string> pars;
partitionHelper(s, res, pars, 0);
return res;
}
private:
int len;
void partitionHelper(std::string &s, std::vector<std::vector<std::string> > &res, std::vector<std::string> &pars, int begin) {
if (begin == len)
res.push_back(pars);
for (int end = begin; end != len; ++end)
if (isPalindrome(s, begin, end)) {
pars.push_back(s.substr(begin, end - begin + 1));
partitionHelper(s, res, pars, end + 1);
pars.pop_back();
}
}
bool isPalindrome(std::string &s, int begin, int end) {
while (begin <= end)
if (s[begin++] != s[end--])
return false;
return true;
}
};