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  1. #include <iostream>
  2. #include <cmath>
  3. using namespace std;
  4.  
  5. int original(int turn) {
  6.     if (turn != 0) {
  7.         if (turn > 0) {
  8.             turn /= 45;
  9.             if (turn < 4) turn = 4;
  10.             if (turn > 8) turn = 8;
  11.         } else {
  12.             turn /= 45;
  13.             if (turn > -4) turn = -4;
  14.             if (turn < -8) turn = -8;
  15.         }
  16.     }
  17.     return turn;
  18. }
  19.  
  20.  
  21. int optimized(int turn) {
  22.     int s=turn>>31,a=turn+s^s,b=(a>360?524288:a>180?a*1457:262144)>>16;
  23.     return b+s^s;
  24. }
  25.  
  26.  
  27. int main() {
  28.     int errors = 0;
  29.     for (int i = -720; i < 720; ++i) if (i != 0) {
  30.         int t1 = original(i);
  31.         int t2 = optimized(i);
  32.         if (t1 != t2) {
  33.             std::cout << "at " << i <<  " expected " << t1 << " got " << t2 << std::endl;
  34.             ++errors;
  35.         }
  36.     }
  37.     std::cout << "errors: " << errors << std::endl;
  38.     return 0;
  39. }
Success #stdin #stdout 0s 3460KB
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stdin
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Standard input is empty
stdout
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errors: 0
https://ideone.com/E7ZqWG
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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