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();
}
}
}
};