题解 | #找位置#

时间复杂度为 O(n)

#include <algorithm>
#include <vector>
using namespace std;

int main()
{
    string  s;
    while (cin >> s)
    {
        vector <vector <int >> v(128);
        for (int i = 0; i < s.size(); i++)
        {
            v[s[i]].push_back(i);
        }
        for (int i = 0; i < s.size(); i++)
        {
            char ch = s[i];
            if (v[ch].size() > 1)
            {
                for(int j = 0; j < v[ch].size(); j++)
                {
                    cout << s[v[ch][j]] << ":" <<v[ch][j];
                    if(j != v[ch].size() - 1) cout << ",";
                    else cout << endl;
                }
                v[ch].clear();
            }
        }
    }
}