Microsoft - MaxEmployeeAttendence (R repititions - 1st step towards DP solution), C++ (gcc)

Language: Layout:

//g++  7.4.0
// https://leetcode.com/discuss/interview-experience/1930164/Microsoft-or-SDE2-or-Hyderabad-or-April-2022-Reject

#include <bits/stdc++.h>

using namespace std;

vector<vector<int>> possible_attendants_at_day;

int MaxEmployeeAttendence (int current_day, int repititions_left, unordered_set<int> employees) {
    if (repititions_left == 0) return employees.size();
    if (current_day < 0) return 0;           // There are no more days & we haven't organised the course for required `repititions`.
    
    int result = 0;
    
    // take the current day
    unordered_set<int> new_employees_set = employees;
    for (int employee : possible_attendants_at_day[current_day]) {
        new_employees_set.insert (employee);
    }
    
    result = max (result, MaxEmployeeAttendence(current_day-1, repititions_left-1, new_employees_set));
    
    // don't take the current day
    result = max (result, MaxEmployeeAttendence(current_day-1, repititions_left, employees));
    
    return result;
}

/*
 * availability[i] - list of days on which ith employee will be available to take the training. [0 <= availability[i][j] < D]
 *
 * total_days (D)  - total number of days in which the training can be conducted.
 *
 * repititions (R) - number of times the training will be repeated in 'total_days' duration.
 *
**/
int MaxEmployeeAttendence (vector<vector<int>>& availability, int total_days, int repititions) {
    possible_attendants_at_day.resize(total_days, {});
    
    for (int employee = 0; employee < availability.size(); employee ++) {
        for (int day : availability[employee]) {
            possible_attendants_at_day [day].push_back(employee);
        }
    }
    
    unordered_set<int> employee_set;
    return MaxEmployeeAttendence (total_days-1, repititions, employee_set);
}

int main() {
    vector<vector<int>> availability = {
        {0, 3, 9},
        {4},
        {1, 4},
        {3, 2},
        {3, 4},
        {7}
    };
    
    cout << MaxEmployeeAttendence (availability, 10, 2) << endl;
    return 0;
}

Show compiler warnings [ + ] Compiler args [ + ] Show input
Compilation time: 2.24 sec, absolute running time: 0.17 sec, cpu time: 0.01 sec, memory peak: 6 Mb, absolute service time: 2,52 sec

Microsoft - MaxEmployeeAttendence (R repititions - 1st step towards DP...