Employee Free Time in C++

Suppose we have given a list of schedules of employees; this represents the working time for each employee. Now suppose each employee has a list of non-overlapping Intervals, these intervals are sorted. We have to find the list of finite intervals representing the common, positive-length free time for all employees, and that will also be in sorted order. We are representing Intervals in the form [x, y], For example, schedule [0][0].start = 1, schedule[0][0].end = 2.

So, if the input is like schedule = [[[1,2],[5,6]],[[1,3]],[[4,10]]], then one of the output will be [[3,4]].

To solve this, we will follow these steps −

• Define one 2D array v

• for initialize i := 0, when i < size of schedule, update (increase i by 1), do

  • for initialize j := 0, when j < size of schedule[i], update (increase j by 1), do

    • insert schedule[i, j] at the end of v

• sort the array v

• Define one 2D array ret

• Define an array temp := v[0]

• for initialize i := 0, when i < size of v, update (increase i by 1), do −

  • if temp[0] < v[i, 1], then −

    • insert {temp[1], v[i, 0]} at the end of ret

    • temp := v[i]

  • Otherwise

    • temp := (if temp[1] < v[i, 1], then v[i], otherwise temp)

• return ret

Let us see the following implementation to get better understanding −

Example

 Live Demo

#include <bits/stdc++.h> using namespace std; void print_vector(vector<vector<auto> > v){    cout << "[";    for(int i = 0; i<v.size(); i++){       cout << "[";       for(int j = 0; j <v[i].size(); j++){          cout << v[i][j] << ", ";       }       cout << "],";    }    cout << "]"<<endl; } class Solution {    public:    static bool cmp(vector<int> a, vector<int> b){       return a[0] < b[0];    }    vector<vector<int>> employeeFreeTime(vector<vector<vector<int>>> schedule) {       vector<vector<int>> v;       for (int i = 0; i < schedule.size(); i++) {          for (int j = 0; j < schedule[i].size(); j++) {             v.push_back(schedule[i][j]);          }       }       sort(v.begin(), v.end(), cmp);       vector<vector<int>> ret;       vector<int> temp = v[0];       for (int i = 0; i < v.size(); i++) {          if (temp[0] < v[i][1]) {             ret.push_back({temp[1], v[i][0]});             temp = v[i];          } else {             temp = temp[1] < v[i][1] ? v[i] : temp;          }       }       return ret;    } }; main(){    Solution ob;    vector<vector<vector<int>>> v = {{{1,2},{5,6}},{{1,3}},{{4,10}}};    print_vector(ob.employeeFreeTime(v)); }

Input

{{{1,2},{5,6}},{{1,3}},{{4,10}}}

Output

[[2, 1, ],[2, 1, ],[3, 4, ],[10, 5, ],]