// Source : https://leetcode.com/problems/word-pattern/
// Author : Hao Chen
// Date : 2015-10-22
/***************************************************************************************
*
* Given a pattern and a string str, find if str follows the same pattern.
* Here follow means a full match, such that there is a bijection between a letter in
* pattern and a non-empty word in str.
*
* Examples:
*
* pattern = "abba", str = "dog cat cat dog" should return true.
* pattern = "abba", str = "dog cat cat fish" should return false.
* pattern = "aaaa", str = "dog cat cat dog" should return false.
* pattern = "abba", str = "dog dog dog dog" should return false.
*
* Notes:
* You may assume pattern contains only lowercase letters, and str contains lowercase
* letters separated by a single space.
*
* Credits:Special thanks to @minglotus6 for adding this problem and creating all test
* cases.
*
***************************************************************************************/
class Solution {
private::
vector split(string str, char delimiter) {
vector internal;
stringstream ss(str); // Turn the string into a stream.
string tok;
while(getline(ss, tok, delimiter)) {
internal.push_back(tok);
}
return internal;
}
public:
bool wordPattern(string pattern, string str) {
unordered_map dict_pattern;
unordered_map dict_string;
int len = pattern.size();
vector strs = split(str, ' ');
if (len != strs.size()) return false;
for(int i=0; i