Restore IP Addresses

来源：互联网发布：搭建apache服务器性能编辑：程序博客网时间：2024/06/03 15:06

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)

class Solution {public:    vector<string> restoreIpAddresses(string s) {        vector<string> ips=restoreIpAddresses(s,4);//常规ip表示法有4个ip段        return ips;    }private:    vector<string> restoreIpAddresses(string s,int restSegment) {        vector<string> ips;        if(restSegment == 1){//最后一个ip段            if(isIpSegment(s)){                ips.push_back(s);            }            return ips;        }        int len = s.size();        for(int i=0;i<3 ;++i){//每个ip段最多3位            string first = s.substr(0,i+1);            if(isIpSegment(first)){                 if(i+1 < len){                     vector<string> rest = restoreIpAddresses(s.substr(i+1,len-i-1),restSegment-1);                     for(int j=0;j<rest.size();++j){                         ips.push_back(first+"."+rest[j]);                     }                 }            }                    }        return ips;    }    bool isIpSegment(string s){//判断一个段是否满足ip地址的要求        int intValue=atoi(s.c_str());bool inScole = (intValue>=0 && intValue<=255);if(!inScole) return false;int len = s.size();if(len>1 && s[0]=='0') return false;return true;    }};

0 0