题解 | #整数与IP地址间的转换#
整数与IP地址间的转换
https://www.nowcoder.com/practice/66ca0e28f90c42a196afd78cc9c496ea
利用 >>> 和 &1 拿到各个位数的数字，效率比直接调用api会好些
let line
let arr = []
let decimalismIP;
while(line = readline()) {
if(line.split('.').length > 2) {
const agencyArr = line.split('.')
agencyArr.forEach(item => {
arr.push(parseInt(item))
})
}else {
decimalismIP = parseInt(line)
}
}
// console.log(arr)
let binaryArr = []
arr.forEach(item => {
const temp = new Array(8)
for(let i=0; i<8; i++) {
temp[7 - i] = item & 1
item >>>= 1
}
binaryArr.push(...temp)
})
const res = parseInt(binaryArr.join(''), 2)
print(res)
let decimalismToIp = new Array(32)
for(let i=0; i<32; i++) {
decimalismToIp[31 - i] = decimalismIP & 1;
decimalismIP >>>= 1;
}
let secondArr = []
let num = 0;
let tempStr = ''
for(let i=0; i<decimalismToIp.length; i++) {
tempStr += decimalismToIp[i]
num++
if(num == 8) {
num = 0
secondArr.push(parseInt(tempStr, 2))
tempStr = ''
}
}
print(secondArr.join('.'))
