length-of-shortest-list.cc

#include <vector>
#include <cassert>
#include <iostream>
#include <forward_list>

using std::cout;
using std::cin;
using std::endl;

using std::vector;
using std::forward_list;

typedef vector<forward_list<int>::iterator> VecItersToList;

int length_of_shortest_list(vector<forward_list<int>> container) {

    int length = container.size();

    VecItersToList vector_list_iterators;
    
    for (int idx = 0; idx < length; ++idx) {
        vector_list_iterators.push_back(container[idx].begin());
    }

    int list_length = 1;

    while (true) {

        for (int idx = 0; idx < length; ++idx) {
            if (vector_list_iterators[idx] != container[idx].end()) {
                if (++vector_list_iterators[idx] == container[idx].end()) {
                    return list_length;
                }
            }
            else {
                return list_length - 1;
            }
        }
        ++list_length;
    }
}


int main() {

    vector<forward_list<int>> test_array_1 =
        {
            {1, 2},
            {0, 3, 1},
            {1, 4, 5, 1},
            {1, 2, 3, 4},
            {1, 2, 3},
            {1, 2, 3, 4, 5, 6},
            {4, 6, 1, 3}
        };
    
    vector<forward_list<int>> test_array_2 =
        {
            {1, 2, 3, 4},
            {5, 6, 7, 8}
        };

    vector<forward_list<int>> test_array_3 =
        {
            {1, 2, 3, 4},
            {5, 6, 7, 8},
            {2, 3, 4},
            {1, 2, 3, 4}
        };

     vector<forward_list<int>> test_array_4 =
        {
            {1, 2, 3, 4},
            {5, 6, 7, 8},
            {1},
            {1, 2, 3, 4}
        };

    assert(length_of_shortest_list(test_array_1) == 2);
    assert(length_of_shortest_list(test_array_2) == 4);
    assert(length_of_shortest_list(test_array_3) == 3);
    assert(length_of_shortest_list(test_array_4) == 1);

    return 0;
}