qset.cc

#include <iostream>
#include <string>
#include <set>
#include <map>
#include <algorithm>
#include <vector>
#include <iterator>
#include <sstream>

using namespace std;
typedef multiset<string> qset;

qset split_to_qset(string line) {
    stringstream ss(line);
    istream_iterator<string> begin(ss);
    istream_iterator<string> end;
    vector<string> vstrings(begin, end);
    qset q(vstrings.begin(), vstrings.end());
    return q;
}

void display_current(qset state) {
    set<string> names(state.begin(), state.end());
    for (const auto name: names) {
        cout << name << "=" << state.count(name) << " ";
    }
    cout << endl;
}

int main(int argc, char const *argv[]) {
    qset state;
    vector<pair<qset, qset>> program;

    for (int i = 0; i < argc; ++i) {
        int val = atoi(argv[i]);
        for (int a = 0; a < val; ++a) {
            state.insert("i" + to_string(i));
        }
    }

    string line;
    while (getline(cin, line)) {
        size_t pos = line.find_first_of('|');
        if (pos == string::npos) continue;
        string first_part = line.substr(0, pos), second_part = line.substr(pos+1);
        program.emplace_back(pair<qset,qset>(split_to_qset(first_part), split_to_qset(second_part)));
    }

    size_t current_line = 0;
    size_t limit = 100000;
    while (current_line < program.size() && --limit) {
        if (includes(state.begin(), state.end(), program[current_line].second.begin(),program[current_line].second.end())) {
            qset diff;
            set_difference(state.begin(), state.end(), program[current_line].second.begin(), program[current_line].second.end(), inserter(diff, diff.begin()));
            state.swap(diff);
            state.insert(program[current_line].first.begin(), program[current_line].first.end());
            current_line = 0;
            display_current(state);
        } else {
            current_line++;
        }
    }

    if (!limit) {
        cerr << "Execution steps limit exceeded" << endl;
        return 1;
    }

    return 0;
}