leetcode Group Anagrams

原题链接：https://leetcode.com/problems/anagrams/

Description

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:

For the return value, each inner list’s elements must follow the lexicographic order.

All inputs will be in lower-case.

以一种奇怪的方式水过去了… (:з」∠)

class Solution {
public:
vector<vector<string>> groupAnagrams(vector<string>& strs) {
if (!strs.size()) return ans;
int n = strs.size();
vector<string> *ret = new vector<string>
;
for (int i = 0; i < n; i++) {
string x = strs[i];
sort(x.begin(), x.end());
if (vis.find(x) == vis.end()) {
vis[x] = i, index.insert(i);
ret[i].push_back(strs[i]);
} else {
int v = vis[x];
vis[strs[i]] = v;
ret[v].push_back(strs[i]);
}
}
for (set<int>::iterator i = index.begin(); i != index.end(); ++i) {
sort(ret[*i].begin(), ret[*i].end());
ans.push_back(ret[*i]);
}
sort(ans.begin(), ans.end(), cmp());
delete []ret;
return ans;
}
private:
struct cmp {
bool operator()(const vector<string> &A, const vector<string> &B) {
int m = (int)A.size(), n = (int)B.size();
return n == m ? A[0] > B[0] : (bool)(n > m);
}
};
set<int> index;
unordered_map<string, int> vis;
vector<vector<string>> ans;
};