Check whether the number formed by concatenating two numbers is a perfect square or not

Given two numbers a and b and the task is to check whether the concatenation of a and b is a perfect square or not.


Input: a = 1, b = 21
Output: Yes
121 = 11 × 11, is a perfect square.

Input: a = 100, b = 100
Output: No
100100 is not a perfect square.

Approach: Initialize the number as strings initially and concatenate them. Convert the string to a number using Integer.valueOf() function. Once the string has been converted to a number, check if the number is a perfect square or not.

Below is the implementation of the above approach.

// Java program to check if the
// concatenation of two numbers
// is a perfect square or not
import java.lang.*;
class GFG {

    // Function to check if the concatenation is
    // a perfect square
    static void checkSquare(String s1, String s2)

        // Function to convert concatenation
        // of strings to a number
        int c = Integer.valueOf(s1 + s2);

        // square root of number
        int d = (int)Math.sqrt(c);

        // check if it is a perfect square
        if (d * d == c) {
        else {

    // Driver Code
    public static void main(String[] args)
        String s1 = "12";
        String s2 = "1";

        checkSquare(s1, s2);


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