find_the_next_perfect_square.cpp

//You might know some pretty large perfect squares. But what about the NEXT one?

//Complete the findNextSquare method that finds the next integral perfect square after the one passed as a parameter. Recall that an integral perfect square is an integer n such that sqrt(n) is also an integer.

//If the parameter is itself not a perfect square then -1 should be returned. You may assume the parameter is non-negative.

//Examples:(Input --> Output)

//121 --> 144
//625 --> 676
//114 --> -1 since 114 is not a perfect square

#include <math.h>

long int findNextSquare(long int sq) {
  long square = sqrt(sq);
  
  if (square * square != sq)
    return -1;
  
  return pow(++square, 2);
}