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  1. #include <iostream>
  2. #include <chrono>
  3. using namespace std;
  4.  
  5. int main() {
  6.  
  7. 	double a[10000],b[10000];
  8. 	for(int i=0;i<10000;i++){
  9. 		b[i]=(double)(rand()+1)/(double)(RAND_MAX+1);
  10. 		a[i]=b[i];
  11. 	}
  12. 	auto start = chrono::steady_clock::now();
  13.  
  14. 	    int x1=0,x2=0,i1,index; 
  15.       for ( i1 = 1; i1 <= 10000; i1++){
  16.                  for ( index = 0; index < 10000; index++){
  17.  
  18.  
  19.                     x1++;
  20.                     if(x1>=100){
  21.                         x1=0;
  22.                         x2++;
  23.                      }
  24.  
  25.                      if (x1 > 10)
  26.                      {
  27.                          a[index] += a[index - 10*1];
  28.                      }
  29.                      if (x2 < 95)
  30.                      {
  31.                          a[index] += a[index + 5*100];
  32.                      }
  33.                  }
  34.              }
  35. auto end = chrono::steady_clock::now();
  36. auto diff = end - start;
  37.  
  38. cout << "method 8: " << chrono::duration <double, nano> (diff).count() << " ns" << endl;
  39.  
  40.  
  41. 				double temp;
  42. 				for(int i=0;i<10000;i++){
  43. 	    		temp=a[i];
  44. 				a[i]=b[i];
  45. 				b[i]=temp;
  46. 	        }
  47.  
  48. 	start = chrono::steady_clock::now();					   
  49.           for ( i1 = 1; i1 <= 10000; i1++){
  50. 			    index=-1;
  51.  
  52.                       for ( x2 = 0; x2 < 100; x2++){
  53. 						  for ( x1 = 0; x1 < 100; x1++){
  54.  
  55.                     index++;
  56.  
  57.                      if (x1 > 10){
  58.                          a[index] += a[index - 10*1];
  59.                      }
  60.                      if (x2 < 95){
  61.                          a[index] += a[index + 5*100];
  62.                      }
  63.                  }
  64.              }
  65. 		  }
  66. end = chrono::steady_clock::now();
  67. diff = end - start;
  68.  
  69. cout << "method 6 " << chrono::duration <double, nano> (diff).count() << " ns" << endl;
  70. 	return 0;
  71. }
Success #stdin #stdout 0s 3456KB
comments (?)
stdin 
Standard input is empty
stdout 
method 8: 462 ns
method 6 297 ns
https://ideone.com/oKVdQI
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

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