コード例 #1
0
ファイル: aroundcenter.cpp プロジェクト: gatieme/LeetCode
	std::string longestPalindrome(std::string s)
	{
  		int n = s.length( );
  		if (n == 0)
  		{
  			return "";
  		}
  		
  		std::string longest = s.substr(0, 1);  // a single char itself is a palindrome
  		for (int center = 0; center < n - 1; center++)		//  循环每个中心
  		{
  			//  以centerw为中心的最长回文串
    		std::string p1 = expandAroundCenter(s, center, center);
    		if (p1.length() > longest.length())
    		{
      			longest = p1;
			}
			
			//  以center和center + 1为中心的最长回文串
    		std::string p2 = expandAroundCenter(s, center, center + 1);
    		if (p2.length() > longest.length())
    		{
      			longest = p2;
  			}
  		}
  		
  		return longest;
	}
コード例 #2
0
 string longestPalindrome(string s) {
     if(s.length()==0 || s.length()==1) return s;
     string max, sub;
     for(int i=0; i<s.length()-1; i++){
         sub = expandAroundCenter(i, i, s);
         if(sub.length() > max.length())
             max = sub;
         sub = expandAroundCenter(i, i+1, s);
         if(sub.length() > max.length())
             max = sub;
     }
     return max;
 }
コード例 #3
0
ファイル: 14_longestPanlin.cpp プロジェクト: stong9/prac
	string longestPalindrome(string s) {
		int n = s.length();
		if (n == 0) return "";
		string longest = s.substr(0, 1);  // a single char itself is a palindrome
		for (int i = 0; i < n-1; i++) {
			string p1 = expandAroundCenter(s, i, i);
			if (p1.length() > longest.length())
			longest = p1;

			string p2 = expandAroundCenter(s, i, i+1);
			if (p2.length() > longest.length())
			longest = p2;
		}
		return longest;
	}
コード例 #4
0
	string longestPalindrome2(string s) 
	{
        int n = s.size();
		string result;
		if (s.empty())
			return "";
		string longest = s.substr(0, 1);
		for (int i = 0; i < n - 1; ++ i)
		{
			string s1 = expandAroundCenter(s, i, i);
			if (s1.size() > longest.size())
				longest = s1;
			string s2 = expandAroundCenter(s, i, i + 1);
			if (s2.size() > longest.size())
				longest = s2;
		}
		return longest;
	}
コード例 #5
0
//第二种写法,从中心拓展
    string longestPalindrome(string s){
        int n=s.length();
        if(n==0){
            return "";
        }
        string longest=s.substr(0,1);
        
        for(int i=0;i<n;i++){
            string p1=expandAroundCenter( s,i,i);//围绕中心i使劲往两边走
            if(p1.length()>=longest.length()){
                longest=p1;
            }
            string p2=expandAroundCenter( s,i,i+1);//围绕中心i使劲往两边走
            if(p2.length()>=longest.length()){
                longest=p2;
            }
        }
        return longest;
    } 
コード例 #6
0
 string longestPalindrome(string s) {
     if (s.empty()) {
         return "";
     }
     int n = s.size();
     int maxlen = 1, start = 0, curlen = 0;
     for(int i = 0; i < n-1; i++) {
         curlen = expandAroundCenter(s, i, i);
         if (curlen > maxlen) {
             maxlen = curlen;
             start = i - curlen/2;
         }
         curlen = expandAroundCenter(s, i, i+1);
         if (curlen > maxlen) {
             maxlen = curlen;
             start = i - (curlen-2)/2;
         }
     }
     string rtn (s, start, maxlen);
     return rtn;
 }
コード例 #7
0
string LongestPalindromicSubstring::longestPalindrome(string s) {
    int n = s.size();

    if (n == 0)
        return "";

    string result = s.substr(0, 1);

    for (int i = 0; i < n - 1; i++) {
        string p1 = expandAroundCenter(s, i, i);

        if (p1.size() > result.size())
            result = p1;

        string p2 = expandAroundCenter(s, i, i + 1);

        if (p2.size() > result.size())
            result = p2;
    }

    return result;
}
コード例 #8
0
char * longestPalindrome(char * s) {
  if (s == NULL)
    return NULL;

  int len = strlen(s);
  int start_position = 0;
  int max_len = 0;
  int i = 0;
  for (; i<len; ++i) {
    int l0 = expandAroundCenter(s, len, i, i);
    int l1 = expandAroundCenter(s, len, i, i+1);
    l0 = l0>l1 ? l0 : l1;
    if (l0 > max_len) {
      max_len = l0;
      start_position = i - (l0-1)/2;
    }
  }
  char * result = (char *)malloc((max_len+1)*sizeof(char));
  strncpy(result, &s[start_position], max_len);
  result[max_len] = '\0';
  return result;
}
コード例 #9
0
 string longestPalindrome(string s) {
     
     if( s.size() == 0 )
         return NULL;
     
     int start = 0, end = 0;
     
     for( int i = 0; i < s.size(); i++ )
     {
         int len1 = expandAroundCenter( s, i, i );
         int len2 = expandAroundCenter( s, i, i + 1 );
         
         int len = max( len1, len2 );
         
         if( len > (end - start) )
         {
             start = i - (len - 1)/2;
             end = i + len/2;
         }
      }
      
      return s.substr(start, end - start + 1);
     
 }