题解 | 找位置

#include <iostream>
using namespace std;

void _measure(int index, string str) {
    char c = str[index];
	// format of output
    cout << c << ":" << index;
    for (int i = index + 1; i < str.size(); i++) {
        if (str[i] == c) cout << "," << c << ":" << i;
    }
    cout << endl;
}

int main() {
    string str;
    while (cin >> str) {
        // measure
        // record the measured char
        string visited = "";
        for (int i = 0; i < str.size(); i++) {
            if (visited.find(str[i]) == string::npos && str.substr(i+1).find(str[i]) != string::npos) {
                // need to be measured : haven't be visited and have other repeat elements
                visited += str[i];
                _measure(i, str);
            }
        }
    }
}