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  1. #include <iostream>
  2. #include <fstream>
  3. #include <vector>
  4. #include <queue>
  5. #include <string>
  6.  
  7. std::vector<int> data = {10, 6, 3, 8, 2, 5};
  8. std::vector<float> test = {10, 8, 4.5, 5.5, 5, 3.5};
  9. std::vector<float> result;
  10.  
  11. const int avg = 2; // rolling average of two
  12.  
  13. /* Use a queue to keep the history and another integer for current sum */
  14. /* Check the queue size before use. */
  15. void rolling_avg(int &next) {
  16.     static int sum = 0;
  17.     static std::queue<int> pool;
  18.  
  19.     if(pool.size() != avg) {
  20.         // pool is not full yet. Add to sum and push in queue.
  21.         sum += next;
  22.         pool.push(next);
  23.     } else {
  24.         // pool is full. Remove the first from sum and add the next data.
  25.         sum -= pool.front();
  26.         pool.pop();
  27.  
  28.         sum += next;
  29.         pool.push(next);
  30.     }
  31.  
  32.     result.push_back((float)sum / pool.size());
  33. }
  34.  
  35.  
  36. void read_dat_and_process(const std::string &filepath) {
  37.     std::cout << "reading file: " << filepath << std::endl;
  38.  
  39.     // Read line by line and get the second token.
  40.     // Ignore some data cleaning in this method for demo only.
  41.     // And ignore proper error handling.
  42.     std::ifstream infile(filepath);
  43.     int line_num = 0, num = 0;
  44.  
  45.     std::cout << "...start processing" << std::endl;
  46.     while(infile >> line_num >> num) {
  47.         std::cout << line_num << " " << num << std::endl;
  48.         /* for every num, run the rolling_avg function to populate the result vector.*/
  49.         rolling_avg(num);
  50.     }
  51.     std::cout << "...end of file" << std::endl;
  52.  
  53.     infile.close();
  54. }
  55.  
  56. int main() {
  57.  
  58.     read_dat_and_process("read_avg_test.dat");
  59.  
  60.     std::cout << "result: ";
  61.     for(auto num : result)
  62.         std::cout << num << " ";
  63.     std::cout << std::endl;
  64.  
  65.  
  66.     /* Sample code for using the method: rolling_avg */
  67.  
  68.     // for(auto num : data)
  69.     //     rolling_avg(num);
  70.  
  71.     // std::cout << "data:   ";
  72.     // for(auto num : data)
  73.     //     std::cout << num << " ";
  74.     // std::cout << std::endl;
  75.  
  76.     // std::cout << "test:   ";
  77.     // for(auto num : test)
  78.     //     std::cout << num << " ";
  79.     // std::cout << std::endl;
  80.  
  81.     // std::cout << "result: ";
  82.     // for(auto num : result)
  83.     //     std::cout << num << " ";
  84.     // std::cout << std::endl;
  85.  
  86.     return 0;
  87. }
Success #stdin #stdout 0s 4428KB
comments (?)
stdin 
Standard input is empty
stdout 
reading file: read_avg_test.dat
...start processing
...end of file
result:
https://ideone.com/3E7EhU
language:
C++ (gcc 8.3)
created:
4 years ago
visibility:
public

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