Maximum length String so that no three consecutive characters are same

Given the maximum occurrences of a, b, and c in a string, the task is to make the string containing only a, b, and c such that no three consecutive characters are the same. If the resultant string equals a+b+c, return the length (a+b+c) otherwise -1.

Examples:

Input:  a = 3, b = 3, c = 3
Output: 9
Explanation: Here is one possible string we can form i.e. 

• a = 3 (a, a, a)
• b = 3 (b, b, b)
• c = 3 (c, c, c)

we can create by adding the alternate likewise first a second b, third c.

• abc
• 1+abc -> abc+abc -> abcabc
• 2+abc -> abcabcabc

So, get the last string abcabcabc (as we can see that there is no 3-time repeating character in the string we got) last well output the length of the string i.e. 9.

Approach: This can be solved with the following idea:

The idea is very simple we can use a simple math formula. 

Below are the steps involved in the implementation of the code:

• First of all, we create an mx var and find the maximum value from a, b, and c.
• Then we can check if mx ≤ (2*(sum of a, b, and c)-mx+1). if this came True then we can simply output the sum of a+b+c.
• Otherwise, we will output -1.

Below is the implementation of the code:

C++

//C++ Implementation
#include <iostream>
using namespace std;

// Function to find maximum length
void getValue(int a, int b, int c)
{

    // Find the maximum value from a, b and c
    int mx = max(a, max(b, c));

    // Using the formula
    if (mx <= (2*(a + b + c) - mx + 1))
    {

        // if it's true we print a + b + c
        cout << a + b + c << endl;
    } else {
        cout << -1 << endl;
    }
}

// Driver code
int main() {
    int a = 3;
    int b = 3;
    int c = 3;

    // Function call
    getValue(a, b, c);

    return 0;
}

Java

import java.util.*;

public class Main {

    public static void getValue(int a, int b, int c) {
        int mx = Math.max(a, Math.max(b, c));

        if (mx <= (2*(a + b + c) - mx + 1)) {
            System.out.println(a + b + c);
        } else {
            System.out.println(-1);
        }
    }

    public static void main(String[] args) {
        int a = 3;
        int b = 3;
        int c = 3;

        getValue(a, b, c);
    }
}

Python

# Python Implementation

# Function to find maximum length


def getValue(a, b, c):

    # Find the maximum value form a, b and c
    mx = max(a, b, c)

    # Using the formula
    if (mx <= (2*(a + b+c)-mx + 1)):

        # if it true we print a + b+c
        print(a + b+c)
    else:
        print(-1)


# Driver code
a = 3
b = 3
c = 3

# Function call
getValue(a, b, c)

C#

// C# Implementation
using System;

class GFG {
    // Function to find maximum length
    static void getValue(int a, int b, int c) {
        // Find the maximum value from a, b, and c
        int mx = Math.Max(a, Math.Max(b, c));

        // Using the formula
        if (mx <= (2 * (a + b + c) - mx + 1)) {

            // if it's true we print a + b + c
            Console.WriteLine(a + b + c);
        } else {
            Console.WriteLine(-1);
        }
    }

    // Driver code
    static void Main(string[] args) {
        int a = 3;
        int b = 3;
        int c = 3;

        // Function call
        getValue(a, b, c);
    }
}

// This code is contributed by Utkarsh Kumar

Javascript

function getValue(a, b, c) {
    let mx = Math.max(a, Math.max(b, c));

    if (mx <= (2 * (a + b + c) - mx + 1)) {
        console.log(a + b + c);
    } else {
        console.log(-1);
    }
}

let a = 3;
let b = 3;
let c = 3;

getValue(a, b, c);

Output

9

Time Complexity: O(1)
Auxiliary Space: O(1)