Find winner of an election where votes are represented as candidate names (original) (raw)

Last Updated : 18 Jul, 2024

Given an array of names of candidates in an election. A candidate's name in the array represents a vote cast on the candidate. Print the name of candidates who received the maximum vote. If there is a tie, print a lexicographically smaller name.

**Examples:

**Input: votes[] = {"john", "johnny", "jackie", "johnny", "john", "jackie", "jamie", "jamie", "john", "johnny", "jamie", "johnny", "john"}
**Output: John
**Explanation: We have four Candidates with name as 'John', 'Johnny', 'jamie', 'jackie'. The candidates John and Johny get maximum votes. Since John is alphabetically smaller.

**Input: votes[] = {"virat", "rohit", "rishabh", "rohit", "virat", "rohit"}
**Output: rohit
**Explanation: We have three Candidates with name as 'virat', 'rohit', 'rishabh'. **rohit get maximum votes.

Try It Yourself

Naive Approach:

A **simple solution is to run two loops and count the occurrences of every word. And then find the maximum count.

Iterate over every string
- Count the occurrence of the current string in the given votes[]
- Maximise the result if count > previous count
return the result

Below is the implementation of the above approach:

C++ `

// C++ program to find winner in an election. #include "bits/stdc++.h" using namespace std;

/* We have four Candidates with name as 'John', 'Johnny', 'jamie', 'jackie'. The votes in String array are as per the votes casted. Print the name of candidates received Max vote. */ void findWinner(vector& votes) { int n = votes.size(); int prevCount = 0; string result = "";

// Iterate over every string
for (int i = 0; i < n; i++) {
    int count = 0;

    // Count the occurrence of current string in the
    // given votes[]
    for (int j = 0; j < n; j++) {
        if (votes[i] == votes[j])
            count++;

        // Maximise the result if count > previous count
        if (count > prevCount) {
            prevCount = count;
            result = votes[i];
        }
        else if (count == prevCount) {
            result = min(result, votes[i]);
        }
    }
}

// return the result
cout << result;

}

// Driver code int main() { vector votes = { "john", "johnny", "jackie", "johnny", "john", "jackie", "jamie", "jamie", "john", "johnny", "jamie", "johnny", "john" };

findWinner(votes);
return 0;

}

Java

import java.io.; import java.util.; import java.util.Vector;

public class Gfg { public static void findWinner(List votes) { int n = votes.size(); int prevCount = 0; String result = "";

    // Iterate over every string
    for (int i = 0; i < n; i++) {
        int count = 0;

        // Count the occurrence of current string in the
        // given votes[]
        for (int j = 0; j < n; j++) {
            if (votes.get(i).equals(votes.get(j))) {
                count++;
            }

            // Maximise the result if count > previous
            // count
            if (count > prevCount) {
                prevCount = count;
                result = votes.get(i);
            }
            else if (count == prevCount) {
                if (votes.get(i).compareTo(result) < 0)
                    result = votes.get(i);
            }
        }
    }

    // return the result
    System.out.println(result);
}

public static void main(String[] args)
{
    List<String> votes = new Vector<String>();
    votes.add("john");
    votes.add("johnny");
    votes.add("jackie");
    votes.add("johnny");
    votes.add("john");
    votes.add("jackie");
    votes.add("jamie");
    votes.add("jamie");
    votes.add("john");
    votes.add("johnny");
    votes.add("jamie");
    votes.add("johnny");
    votes.add("john");

    findWinner(votes);
}

}

Python

Python program to find winner in an election.

import math

We have four Candidates with name as 'John',

#'Johnny', 'jamie', 'jackie'.

The votes in String array are as per the

#votes casted. Print the name of candidates #received Max vote. */ def findWinner(votes): n = len(votes); prevCount = 0; result = "";

# Iterate over every string
for i in range(0, n): 
    count = 0;

    # Count the occurrence of current string in the
    # given votes[]
    for j in range(0, n): 
        if (votes[i] == votes[j]):
            count += 1;

        # Maximise the result if count > previous count
        if (count > prevCount):
            prevCount = count;
            result = votes[i];
    
        elif (count == prevCount) :
            result = min(result, votes[i]);
    
# return the result
print(result);

Driver code

votes = [ "john", "johnny", "jackie", "johnny", "john", "jackie", "jamie", "jamie", "john", "johnny", "jamie", "johnny", "john" ];

findWinner(votes);

This code is contributed by agrawalpoojaa976.

C#

using System; using System.Linq; using System.Collections.Generic;

class Gfg { public static void findWinner(List votes) { int n = votes.Count; int prevCount = 0; string result = "";

// Iterate over every string
for (int i = 0; i < n; i++) {
  int count = 0;

  // Count the occurrence of current string in the
  // given votes[]
  for (int j = 0; j < n; j++) {
    if (votes[i] == votes[j]) {
      count++;
    }

    // Maximise the result if count > previous
    // count
    if (count > prevCount) {
      prevCount = count;
      result = votes[i];
    }
    else if (count == prevCount) {
      if (votes[i].CompareTo(result) < 0)
        result = votes[i];
    }
  }
}

// return the result
Console.WriteLine(result);

} public static void Main(string[] args) { List votes = new List() { "john", "johnny", "jackie", "johnny", "john", "jackie", "jamie", "jamie", "john", "johnny", "jamie", "johnny", "john" }; findWinner(votes); } }

// This code is contributed by divya_p123.

JavaScript

function findWinner(votes) { let n = votes.length; let prevCount = 0; let result = "";

// Iterate over every string 
for (let i = 0; i < n; i++) { 
    let count = 0; 

    // Count the occurrence of current string in the 
    // given votes[] 
    for (let j = 0; j < n; j++) { 
        if (votes[i] == votes[j]) 
            count++; 

        // Maximise the result if count > previous count 
        if (count > prevCount) { 
            prevCount = count; 
            result = votes[i]; 
        } 
        else if (count == prevCount) { 
            result = Math.min(result, votes[i]); 
        } 
    } 
} 

// return the result 
console.log(result);

}

// Driver code let votes = ["john", "johnny", "jackie", "johnny", "john", "jackie", "jamie", "jamie", "john", "johnny", "jamie", "johnny", "john"];

findWinner(votes);

// This code is contributed by factworx412

**Time Complexity: O(n * n * MAX_WORD_LEN).
**Auxiliary Space: O(MAX_WORD_LEN)

Find winner of an election where votes are represented as candidate names using Hashing:

An **efficient solution is to use Hashing. Insert all votes in a hash map and keep track of counts of different names. Finally, traverse the map and print the person with the maximum votes.

Follow the steps below to solve the problem:

Create a map of string, value pair
Now iterate on the votes array and increment the count of every string
Traverse the map and the string having maximum count store it as a string variable
If there is a tie pick the smaller one

Below is the Implementation of the above approach:

C++ `

// C++ program to find winner in an election. #include "bits/stdc++.h" using namespace std;

// Insert all votes in a hashmap
unordered_map<string, int> mapObj;
for (auto& str : votes) {
    mapObj[str]++;
}

// Traverse through map to find the candidate
// with maximum votes.
int maxValueInMap = 0;
string winner;
for (auto& entry : mapObj) {
    string key = entry.first;
    int val = entry.second;
    if (val > maxValueInMap) {
        maxValueInMap = val;
        winner = key;
    }

    // If there is a tie, pick lexicographically
    // smaller.
    else if (val == maxValueInMap && winner > key)
        winner = key;
}
cout << winner << endl;

}

// Driver code int main() { vector votes = { "john", "johnny", "jackie", "johnny", "john", "jackie", "jamie", "jamie", "john", "johnny", "jamie", "johnny", "john" };

findWinner(votes);
return 0;

}

Java

// Java program to find winner in an election. import java.util.*;

public class ElectoralVotingBallot { /* We have four Candidates with name as 'John', 'Johnny', 'jamie', 'jackie'. The votes in String array are as per the votes casted. Print the name of candidates received Max vote. */ public static void findWinner(String votes[]) { // Insert all votes in a hashmap Map<String, Integer> map = new HashMap<String, Integer>(); for (String str : votes) { if (map.keySet().contains(str)) map.put(str, map.get(str) + 1); else map.put(str, 1); }

    // Traverse through map to find the candidate
    // with maximum votes.
    int maxValueInMap = 0;
    String winner = "";
    for (Map.Entry<String, Integer> entry :
         map.entrySet()) {
        String key = entry.getKey();
        Integer val = entry.getValue();
        if (val > maxValueInMap) {
            maxValueInMap = val;
            winner = key;
        }

        // If there is a tie, pick lexicographically
        // smaller.
        else if (val == maxValueInMap
                 && winner.compareTo(key) > 0)
            winner = key;
    }
    System.out.println(winner);
}

// Driver code
public static void main(String[] args)
{
    String[] votes
        = { "john", "johnny", "jackie", "johnny",
            "john", "jackie", "jamie",  "jamie",
            "john", "johnny", "jamie",  "johnny",
            "john" };

    findWinner(votes);
}

}

Python

Python3 program to find winner in an election.

from collections import defaultdict

''' We have four Candidates with name as 'John', 'Johnny', 'jamie', 'jackie'. The votes in String array are as per the votes casted. Print the name of candidates received Max vote. '''

def findWinner(votes):

# Insert all votes in a hashmap
mapObj = defaultdict(int)

for st in votes:
    mapObj[st] += 1

# Traverse through map to find the
# candidate with maximum votes.
maxValueInMap = 0
winner = ""

for entry in mapObj:
    key = entry
    val = mapObj[entry]

    if (val > maxValueInMap):
        maxValueInMap = val
        winner = key

    # If there is a tie, pick lexicographically
    # smaller.
    elif (val == maxValueInMap and
             winner > key):
        winner = key

print(winner)

Driver code

if name == "main":

votes = ["john", "johnny", "jackie",
         "johnny", "john", "jackie",
         "jamie", "jamie", "john",
         "johnny", "jamie", "johnny",
         "john"]

findWinner(votes)

This code is contributed by ukasp

C#

// C# program to find winner in an election. using System; using System.Collections.Generic;

public class ElectoralVotingBallot { /* We have four Candidates with name as 'John', 'Johnny', 'jamie', 'jackie'. The votes in String array are as per the votes casted. Print the name of candidates received Max vote. */ public static void findWinner(String[] votes) { // Insert all votes in a hashmap Dictionary<String, int> map = new Dictionary<String, int>(); foreach(String str in votes) { if (map.ContainsKey(str)) map[str] = map[str] + 1; else map.Add(str, 1); }

    // Traverse through map to find the candidate
    // with maximum votes.
    int maxValueInMap = 0;
    String winner = "";
    foreach(KeyValuePair<String, int> entry in map)
    {
        String key = entry.Key;
        int val = entry.Value;
        if (val > maxValueInMap) {
            maxValueInMap = val;
            winner = key;
        }

        // If there is a tie, pick lexicographically
        // smaller.
        else if (val == maxValueInMap
                 && winner.CompareTo(key) > 0)
            winner = key;
    }
    Console.WriteLine(winner);
}

// Driver code
public static void Main(String[] args)
{
    String[] votes
        = { "john", "johnny", "jackie", "johnny",
            "john", "jackie", "jamie",  "jamie",
            "john", "johnny", "jamie",  "johnny",
            "john" };

    findWinner(votes);
}

}

// This code is contributed by PrinciRaj1992

JavaScript

// Javascript program to find winner in an election.

/* We have four Candidates with name as 'John', 'Johnny', 'jamie', 'jackie'. The votes in String array are as per the votes casted. Print the name of candidates received Max vote. */ function findWinner(votes) { let map = new Map(); for (let i = 0; i < votes.length; i++) { if (map.has(votes[i])) { map.set(votes[i], map.get(votes[i]) + 1); } else map.set(votes[i], 1); }

// Traverse through map to find the candidate // with maximum votes. let maxValueInMap = 0; let winner = ""; for (let [key, value] of map.entries()) { let Key = key; let val = value; if (val > maxValueInMap) { maxValueInMap = val; winner = key; }

// If there is a tie, pick lexicographically
// smaller.
else if (val == maxValueInMap && winner > Key) winner = Key;

} console.log(winner); }

// Driver code let votes = [ "john", "johnny", "jackie", "johnny", "john", "jackie", "jamie", "jamie", "john", "johnny", "jamie", "johnny", "john", ]; findWinner(votes);

Time Complexity: O(N), where N is the total number of votes.
Auxiliary Space: O(N),** since unordered_map data structure is used.

Another **efficient solution is to use Trie. Please refer most frequent word in an array of strings.