🌵93. Restore IP Addresses
https://leetcode.com/problems/restore-ip-addresses/
js
/**
* @param {string} s
* @return {string[]}
*/
var restoreIpAddresses = function(s) {
var result = []
buildIp(s, [], result)
return result
}
function buildIp(s, nums, result) {
if (nums.length === 4) {
if (!s) {
result.push(nums.join('.'))
}
return
}
for (let i = 0; i < 3; i++) {
if (i >= s.length) {
return
}
if (i > 0 && s[0] === '0') {
return
}
let num = +s.substring(0, i + 1)
if (num <= 255) {
buildIp(s.substring(i + 1), nums.concat([num]), result)
}
}
}py
class Solution(object):
def restoreIpAddresses(self, s):
"""
:type s: str
:rtype: List[str]
"""
result = []
self.buildIp(s, [], result)
return result
def buildIp(self, s, nums, result):
if len(nums) == 4:
if not s:
result.append('.'.join(nums))
return
for i in range(3):
if i >= len(s):
return
if i > 0 and s[0] == '0':
return
if int(s[:i + 1]) <= 255:
self.buildIp(s[i + 1:], nums + [s[:i + 1]], result)