fork download
copy 
  1. #include<bits/stdc++.h>
  2. using namespace std;
  3.  
  4. int main() {
  5.     int n, k;
  6.     cin >> n >> k;
  7.     cin.ignore();  // important to consume the newline after k
  8.  
  9.     vector<string> arr(n);
  10.     vector<int> t(1440, 0);  // minutes in a day
  11.  
  12.     // Read each line properly
  13.     for (int i = 0; i < n; i++) {
  14.         getline(cin, arr[i]);
  15.         while (arr[i].empty()) getline(cin, arr[i]); // skip empty lines
  16.     }
  17.  
  18.     // Parse and mark time intervals
  19.     for (string s : arr) {
  20.         istringstream ss(s);
  21.         string name, activity, start, end;
  22.         ss >> name >> activity >> start >> end;
  23.  
  24.         if (start.size() < 5 || end.size() < 5) continue; // skip bad lines
  25.  
  26.         int lhh = stoi(start.substr(0, 2));
  27.         int lmm = stoi(start.substr(3, 2));
  28.         int rhh = stoi(end.substr(0, 2));
  29.         int rmm = stoi(end.substr(3, 2));
  30.         int L = 60 * lhh + lmm;
  31.         int R = 60 * rhh + rmm;
  32.  
  33.         t[L]++;
  34.         if (R != 1439) t[R + 1]--;
  35.     }
  36.  
  37.     // Build prefix sum
  38.     for (int i = 1; i < 1440; i++) {
  39.         t[i] += t[i - 1];
  40.     }
  41.  
  42.     // Find k-length zero interval
  43.     int length = 0, time = -1;
  44.     for (int i = 0; i < 1440; i++) {
  45.         if (t[i] == 0) {
  46.             length++;
  47.             if (length == k) {
  48.                 time = i - k + 1;
  49.                 break;
  50.             }
  51.         } else {
  52.             length = 0;
  53.         }
  54.     }
  55.  
  56.     if (time == -1)
  57.         cout << "No free slot" << endl;
  58.     else
  59.         cout << setw(2) << setfill('0') << time / 60 << ":"
  60.              << setw(2) << setfill('0') << time % 60 << endl;
  61.  
  62.     return 0;
  63. }
  64.  
Success #stdin #stdout 0.01s 5328KB
comments (?)
stdin
copy 
3 60 
Alex sleep 00:00 08:00
Sam sleep 07:00 13:00
Alex lunch 12:30 13:59
stdout
copy 
14:00
https://ideone.com/hl6PXF
language:
C++ (gcc 8.3)
created:
6 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!