Dictionaries and Maps
Source: Hacker Rank
Task
Given n names and phone numbers, assemble a phone book that maps friends' names to their respective phone numbers. You will then be given an unknown number of names to query your phone book for. For each name queried, print the associated entry from your phone book on a new line in the form name=phoneNumber; if an entry for name is not found, print Not found instead.
Note: Your phone book should be a Dictionary/Map/HashMap data structure.
Input Format
The first line contains an integer, n, denoting the number of entries in the phone book.
Each of the n subsequent lines describes an entry in the form of 2 space-separated values on a single line. The first value is a friend's name, and the second value is an 8-digit phone number.
After the n lines of phone book entries, there are an unknown number of lines of queries. Each line (query) contains a name to look up, and you must continue reading lines until there is no more input.
Note: Names consist of lowercase English alphabetic letters and are first names only.
Constraints
1 <= n <= 10^5
1 <= queries <= 10^5
Output Format
On a new line for each query, print Not found if the name has no corresponding entry in the phone book; otherwise, print the full name and phoneNumber in the format name=phoneNumber.
Sample Input
3
sam 99912222
tom 11122222
harry 12299933
sam
edward
harry
Sample Output
sam=99912222
Not found
harry=12299933
Explanation
We add the following n = 3 (Key,Value) pairs to our map so it looks like this:
phoneBook = {(sam, 99912222), (tom, 11122222), (harry, 12299933)}
We then process each query and print key=value if the queried key is found in the map; otherwise, we print "Not found".
Query 0: sam
Sam is one of the keys in our dictionary, so we print sam=99912222.
Query 1: edward
Edward is not one of the keys in our dictionary, so we print Not found.
Query 2: harry
Harry is one of the keys in our dictionary, so we print harry=12299933.
My solution:
C#:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 | using System; using System.Collections; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace DictionariesAndMaps { class Program { static void Main(string[] args) { int n = Convert.ToInt32(Console.ReadLine()); Hashtable ht = new Hashtable(); //reading for (int aux = 0; aux < n; aux++) { string[] a_temp = Console.ReadLine().Split(' '); string name = a_temp[0]; int num = Convert.ToInt32(a_temp[1]); ht.Add(name, num); } //retriving values while (true) { string readNameToRetrive = Console.ReadLine(); if (readNameToRetrive == "") return; if (ht.ContainsKey(readNameToRetrive)) { Console.WriteLine(readNameToRetrive + "=" + ht[readNameToRetrive]); } else Console.WriteLine("Not found"); } } } } |