C++ map 使用范例

#include <iostream>
#include <string>
#include <cctype>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;

map<string, int> cnt;
vector<string> words;

// 将单词 s 进行标准化
string repr(const string &s)
{
    string ans = s;
    for (int i = 0; i < ans.length(); i++)
        ans[i] = tolower(ans[i]);
    sort(ans.begin(), ans.end());
    return ans;
}

int main()
{
    string s;
    while (cin >> s)
    {
        if (s[0] == '#') break;
        words.push_back(s);
        string r = repr(s);
        if (!cnt.count(r)) cnt[r] = 0;
        cnt[r]++;
    }
    vector<string> ans;
    for (int i = 0; i < words.size(); i++)
        if (cnt[repr(words[i])] == 1) ans.push_back(words[i]);
    sort(ans.begin(), ans.end());
    for (int i = 0; i < ans.size(); i++)
        cout << ans[i] << "
";
    return 0;
}