Given a pattern and a string s, find if s 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 s.
Example 1:
Input: pattern = "abba", s = "dog cat cat dog" Output: true Example 2:
Input: pattern = "abba", s = "dog cat cat fish" Output: false Example 3:
Input: pattern = "aaaa", s = "dog cat cat dog" Output: false Example 4:
Input: pattern = "abba", s = "dog dog dog dog" Output: false
Constraints:
1 <= pattern.length <= 300 pattern contains only lower-case English letters. 1 <= s.length <= 3000 s contains only lower-case English letters and spaces ' '. s does not contain any leading or trailing spaces. All the words in s are separated by a single space.
public class Solution {
public bool WordPattern(string pattern, string s) {
var words = s.Split(' ');
if(pattern.Length!=words.Length){
return false;
}
var map = new Dictionary<char,string>();
var map2 = new Dictionary<string,char>();
for(int i=0;i<words.Length;i++){
if(!map.ContainsKey(pattern[i])){
map.Add(pattern[i],words[i]);
}
if(!map2.ContainsKey(words[i])){
map2.Add(words[i],pattern[i]);
}
}
for(int i=0;i<words.Length;i++){
if(map[pattern[i]]!=words[i]){
return false;
}
if(map2[words[i]]!=pattern[i]){
return false;
}
}
return true;
}
}Time Complexity: O(n)
Space Complexity: O(n)
