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### by Sumit Chourasia | Sep 28, 2020 | Category :coding | Tags : algorithmडेटा-संरचनाआसानhash-tableleetcode

#### Keyboard Row - Hash Table - Easy - LeetCode - मिनी टीवी

Given a List of words, return the words that can be typed using letters of alphabet on only one row's of American keyboard like the image below.

Example:

Input: ["Hello", "Alaska", "Dad", "Peace"]
Output: ["Alaska", "Dad"]

Note:

You may use one character in the keyboard more than once.
You may assume the input string will only contain letters of alphabet.

``````public class Solution {
public string[] FindWords(string[] words) {
if(words.Length==0){
return words;
}

var strArr = new string[]{"qwertyuiop", "asdfghjkl", "zxcvbnm"};
var map = new Dictionary<char,int>();
for(int i=0;i<strArr.Length;i++){
for(int j=0;j<strArr[i].Length;j++){
map.Add(strArr[i][j],i);
}
}

var result = new List<string>();
for(int i=0;i<words.Length;i++){
var str =words[i].ToLower();
int index = map[str[0]];
bool found = true;
for(int j=1;j<str.Length;j++){
if(map[str[j]]!=index){
found = false;
break;
}
}
if(found){
result.Add(words[i]);
}
}

return result.ToArray();
}
}``````

Time Complexity: O(m*n)

Space Complexity: O(m*n)

Where m is the number of strings and n is the maximum character in the string.

Contributed By: Sumit Chourasia
Contributed By: Sumit Chourasia
Contributed By: Sumit Chourasia
Contributed By: Sumit Chourasia