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.
代码语言：javascript复制保证1对1的映射
public boolean wordPattern(String pattern, String str) {
if (pattern == null || str == null) {
return false;
}
String[] strs = str.split(" ");
if (pattern.length() != strs.length) {
return false;
}
Map<Character, String> map = new HashMap<Character, String>();
for (int i = 0; i < pattern.length(); i ) {
char c = pattern.charAt(i);
if (map.containsKey(c)) {
if (!map.get(c).equals(strs[i])) {
return false;
}
} else {
// 保证1对1的映射
if (map.containsValue(strs[i])) {
return false;
}
map.put(c, strs[i]);
}
}
return true;
}
