문제

내 코드

let fs = require("fs");
let input = fs.readFileSync("/dev/stdin").toString().trim();

let num = Number(input);

function solution(n) {
  let cnt = 0;

  for (let i = 1; i <= n; i++) {
    let hundreds = Math.floor((i % 1000) / 100);
    let tens = Math.floor((i % 100) / 10);
    let units = i % 10;

    if (i < 100) {
      cnt++;
    } else if (100 <= i && i < 1000) {
      if (hundreds - tens === tens - units) {
        cnt++;
      }
    }
  }

  return cnt;
}

console.log(solution(num));