Group Anagrams

Total Accepted: 57578 Total Submissions: 226493 Difficulty: Medium

Given an array of strings, group anagrams together.

For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"], 
Return:

[
  ["ate", "eat","tea"],
  ["nat","tan"],
  ["bat"]
]

Note:

1. For the return value, each inner list's elements must follow the lexicographic order.
2. All inputs will be in lower-case.

 (E) Valid Anagram (E) Group Shifted Strings

 

先对每个字符串排序，生成新的串，再对新的串排序，排序好的字符串就是按anagrams规则放在一起

struct Node{
    string origin;
    string str;
    Node(string& originValue,string& strValue):origin(originValue),str(strValue){}
};
int CompStr(const string& lhs,const string& rhs)
{
    int i=0;
    while(i<lhs.size() && i<rhs.size()){
        if(lhs[i] < rhs[i]){
            return 1;
        }else if(lhs[i] > rhs[i]){
            return -1;
        }
        i++;
    }
    if(i==lhs.size() && i==rhs.size()){
        return 0;
    }
    return i<rhs.size() ? 1:-1;
}
bool CompNode(const Node& lhs,const Node& rhs){
    int res = CompStr(lhs.str,rhs.str);
    if(res == 0){
        res = CompStr(lhs.origin,rhs.origin);
    }
    return res==1 ? true:false;
}
class Solution {
public:
    vector<vector<string>> groupAnagrams(vector<string>& strs) {
        int strsSize = strs.size();
        vector<Node> nodes;
        for(int i=0;i<strsSize;i++){
            string str = strs[i];
            sort(str.begin(),str.end());
            nodes.push_back(Node(strs[i],str));
        }
        sort(nodes.begin() ,nodes.end(),CompNode);
        vector<vector<string>> res;
        vector<string> group;
        for(int i=0;i<strsSize;i++){
            if(i>0 && nodes[i].str!=nodes[i-1].str){
                res.push_back(group);
                group.clear();
            }
            group.push_back(nodes[i].origin);
        }
        res.push_back(group);
        return res;
    }
};

Next challenges: (E) Valid Anagram (E) Group Shifted Strings