Find the first maximum length even word from a string

Difficulty Level : Easy
Last Updated : 21 Apr, 2021

Given a string of words separated by spaces. The task is to find the first maximum length even word from the string. Eg: “You are given an array of n numbers” The answer would be “an” and not “of” because “an” comes before “of”.
Examples:

Input:  "this is a test string"
Output:  string
Even length words are this, is, test, string. Even
maximum length word is string.

Input:  "geeksforgeeks is a platform for geeks"
Output:  platform
Only even length word is platform.

Approach: The idea is to traverse the input string and find length of each word. Check if the length of word is even or not. If even, then compare length with maximum length found so far. If length is strictly greater than maximum length then store current word as required string.
Below is the implementation of above approach:

C++

// C++ program to find maximum length even word
 
#include <bits/stdc++.h>
using namespace std;
 
// Function to find maximum length even word
string findMaxLenEven(string str)
{
    int n = str.length();
 
    int i = 0;
 
    // To store length of current word.
    int currlen = 0;
 
    // To store length of maximum length word.
    int maxlen = 0;
 
    // To store starting index of maximum
    // length word.
    int st = -1;
 
    while (i < n) {
 
        // If current character is space then
        // word has ended. Check if it is even
        // length word or not. If yes then
        // compare length with maximum length
        // found so far.
        if (str[i] == ' ') {
            if (currlen % 2 == 0) {
                if (maxlen < currlen) {
                    maxlen = currlen;
                    st = i - currlen;
                }
            }
 
            // Set currlen to zero for next word.
            currlen = 0;
        }
        else {
            // Update length of current word.
            currlen++;
        }
 
        i++;
    }
 
    // Check length of last word.
    if (currlen % 2 == 0) {
        if (maxlen < currlen) {
            maxlen = currlen;
            st = i - currlen;
        }
    }
 
    // If no even length word is present
    // then return -1.
    if (st == -1)
        return "-1";
 
    return str.substr(st, maxlen);
}
 
// Driver code
int main()
{
    string str = "this is a test string";
 
    cout << findMaxLenEven(str);
 
    return 0;
}

Java

// Java program to find maximum length even word
class GFG
{
     
// Function to find maximum length even word
static String findMaxLenEven(String str)
{
    int n = str.length();
 
    int i = 0;
 
    // To store length of current word.
    int currlen = 0;
 
    // To store length of maximum length word.
    int maxlen = 0;
 
    // To store starting index of maximum
    // length word.
    int st = -1;
 
    while (i < n)
    {
 
        // If current character is space then
        // word has ended. Check if it is even
        // length word or not. If yes then
        // compare length with maximum length
        // found so far.
        if (str.charAt(i) == ' ')
        {
            if (currlen % 2 == 0)
            {
                if (maxlen < currlen)
                {
                    maxlen = currlen;
                    st = i - currlen;
                }
            }
 
            // Set currlen to zero for next word.
            currlen = 0;
        }
        else
        {
            // Update length of current word.
            currlen++;
        }
 
        i++;
    }
 
    // Check length of last word.
    if (currlen % 2 == 0)
    {
        if (maxlen < currlen)
        {
            maxlen = currlen;
            st = i - currlen;
        }
    }
 
    // If no even length word is present
    // then return -1.
    if (st == -1)
        return "-1";
 
    return str.substring(st, st + maxlen);
}
 
// Driver code
public static void main(String args[])
{
    String str = "this is a test string";
 
    System.out.println( findMaxLenEven(str));
}
}
 
// This code is contributed by Arnab Kundu

Python 3

# Python3 program to find maximum
# length even word
 
# Function to find maximum length
# even word
def findMaxLenEven(str):
    n = len(str)
    i = 0
 
    # To store length of current word.
    currlen = 0
 
    # To store length of maximum length word.
    maxlen = 0
 
    # To store starting index of maximum
    # length word.
    st = -1
 
    while (i < n):
 
        # If current character is space then
        # word has ended. Check if it is even
        # length word or not. If yes then
        # compare length with maximum length
        # found so far.
        if (str[i] == ' '):
            if (currlen % 2 == 0):
                if (maxlen < currlen):
                    maxlen = currlen
                    st = i - currlen
 
            # Set currlen to zero for next word.
            currlen = 0
         
        else :
             
            # Update length of current word.
            currlen += 1
 
        i += 1
 
    # Check length of last word.
    if (currlen % 2 == 0):
        if (maxlen < currlen):
            maxlen = currlen
            st = i - currlen
 
    # If no even length word is present
    # then return -1.
    if (st == -1):
        print("trie")
        return "-1"
     
    return str[st: st + maxlen]
 
# Driver code
if __name__ == "__main__":
     
    str = "this is a test string"
 
    print(findMaxLenEven(str))
 
# This code is contributed by Ita_c

C#

// C# program to find maximum length even word
 
using System;
 
class GFG
{
     
    // Function to find maximum length even word
    static String findMaxLenEven(string str)
    {
        int n = str.Length;
     
        int i = 0;
     
        // To store length of current word.
        int currlen = 0;
     
        // To store length of maximum length word.
        int maxlen = 0;
     
        // To store starting index of maximum
        // length word.
        int st = -1;
     
        while (i < n)
        {
     
            // If current character is space then
            // word has ended. Check if it is even
            // length word or not. If yes then
            // compare length with maximum length
            // found so far.
            if (str[i] == ' ')
            {
                if (currlen % 2 == 0)
                {
                    if (maxlen < currlen)
                    {
                        maxlen = currlen;
                        st = i - currlen;
                    }
                }
     
                // Set currlen to zero for next word.
                currlen = 0;
            }
            else
            {
                // Update length of current word.
                currlen++;
            }
     
            i++;
        }
     
        // Check length of last word.
        if (currlen % 2 == 0)
        {
            if (maxlen < currlen)
            {
                maxlen = currlen;
                st = i - currlen;
            }
        }
     
        // If no even length word is present
        // then return -1.
        if (st == -1)
            return "-1";
     
        return str.Substring(st, maxlen);
    }
 
    // Driver code
    public static void Main()
    {
        string str = "this is a test string";
     
        Console.WriteLine(findMaxLenEven(str));
    }
    // This code is contributed by Ryuga
}

Javascript

<script>
 
 
// Javascript program to find maximum length even word
 
// Function to find maximum length even word
function findMaxLenEven(str)
{
    var n = str.length;
 
    var i = 0;
 
    // To store length of current word.
    var currlen = 0;
 
    // To store length of maximum length word.
    var maxlen = 0;
 
    // To store starting index of maximum
    // length word.
    var st = -1;
 
    while (i < n) {
 
        // If current character is space then
        // word has ended. Check if it is even
        // length word or not. If yes then
        // compare length with maximum length
        // found so far.
        if (str[i] == ' ') {
            if (currlen % 2 == 0) {
                if (maxlen < currlen) {
                    maxlen = currlen;
                    st = i - currlen;
                }
            }
 
            // Set currlen to zero for next word.
            currlen = 0;
        }
        else {
            // Update length of current word.
            currlen++;
        }
 
        i++;
    }
 
    // Check length of last word.
    if (currlen % 2 == 0) {
        if (maxlen < currlen) {
            maxlen = currlen;
            st = i - currlen;
        }
    }
 
    // If no even length word is present
    // then return -1.
    if (st == -1)
        return "-1";
 
    return str.substr(st, maxlen);
}
 
// Driver code
var str = "this is a test string";
document.write( findMaxLenEven(str));
 
// This code is contributed by noob2000.
</script>

Output:

string

Time Complexity: O(N), where N is the length of the string.
Auxiliary Space: O(1)

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Table of Contents

Find the first maximum length even word from a string

C++

Java

Python 3

C#

Javascript

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