Mahir freeCodeCamp • project-euler-problems-201-to-300

Problem 206: Concealed Square

Ringkasan Tantangan

Find the unique positive integer whose square has the form 1_2_3_4_5_6_7_8_9_0, where each "_" is a single digit.

Find the unique positive integer whose square has the form 1_2_3_4_5_6_7_8_9_0, where each ”_” is a single digit.

💡 Lihat Solusi

function concealedSquare() {
  const pattern = /^1.2.3.4.5.6.7.8.9.0$/;
  for (let i = 1010101010; i <= 1389026623; i += 10) {
    const square = (BigInt(i) * BigInt(i)).toString();
    if (pattern.test(square)) return i;
  }
  return -1;
}