LEETCODE: Restore IP Addresses

来源：互联网发布：域名代理商哪个好编辑：程序博客网时间：2024/06/05 15:11

Given a string containing only digits, restore it by returning all possible valid IP address combinations.

For example:
Given "25525511135",

return ["255.255.11.135", "255.255.111.35"]. (Order does not matter)

忍不住又做了一题！

class Solution {public:    void getAddresses(vector<string> &results, string s, string temp, int segment) {        if(s.length() < segment) return;        if(segment == 1) {            if(s.length() >= 2 && s[0] == '0') return;            if(s.length() < 3 || (s.length() == 3 && s <= "255"))                results.push_back(temp + "." + s);             return;        }                string s0(s, 0, 1);        if(s.length() - 1 <= (segment - 1) * 3) {            string newstr = temp + (segment == 4 ? "" : ".");            newstr += s0;            getAddresses(results, s.substr(1, s.length() - 1), newstr, segment - 1);        }        if(s[0] == '0')return;        string s1(s, 0, 2);        if(s.length() - 2 <= (segment - 1) * 3) {            string newstr = temp + (segment == 4 ? "" : ".");            newstr += s1;            getAddresses(results, s.substr(2, s.length() - 2), newstr, segment - 1);        }        if(s[0] == '0' && s[1] == '0')return;        string s2(s, 0, 3);        if(s.length() - 3 <= (segment - 1) * 3 && s2 <= "255") {            string newstr = temp + (segment == 4 ? "" : ".");            newstr += s2;            getAddresses(results, s.substr(3, s.length() - 3), newstr, segment - 1);        }    }    vector<string> restoreIpAddresses(string s) {        if(s.length() < 3 || s.length() > 12) return vector<string>();        vector<string> results;        string temp;        getAddresses(results, s, temp, 4);        return results;    }};

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