题解 | #判断两个IP是否属于同一子网#|

暴力循环遍历,JavaScript直接循环

const data = [
  readline().split("."),
  readline().split("."),
  readline().split("."),
];
let result = 0;
let theString = "";//掩码二进制的字符串格式;
for (let i = 0; i < 4; i++) {
  const num0 = Number(data[0][i]);
  const num1 = Number(data[1][i]);
  const num2 = Number(data[2][i]);
  const thisString = `00000000${num0.toString(2)}`.slice(-8);//掩码转二进制;
  theString += thisString;

  if (
    num0 < 0 ||
    num0 > 255 ||
    num1 < 0 ||
    num1 > 255 ||
    num2 < 0 ||
    num2 > 255
  ) {
    result = 1;//范围不对,直接报错退出;
    break;
  }
  if ((num0 & num1) !== (num0 & num2)) {
    result = 2;//证明不是子网,但后续ip可能有错,所以只是跳过一次循环;
    continue;
  }
}
if (!/^1{0,}0{0,}$/.test(theString)) {
  result = 1;//掩码二进制格式不对,直接退出;
}

console.log(result);