Employee Free Time in C++

C++Server Side ProgrammingProgramming

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, ],]
raja
Published on 11-Jul-2020 11:51:19
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