20.计算速度最快的valarray

 1 #include <string>
 2 #include <iostream>
 3 //用于计算,计算的性能高于vector与array
 4 #include <valarray>
 5 #include <algorithm>
 6 using namespace std;
 7 
 8 
 9 void main()
10 {
11     const double PI = 3.1415926;
12     valarray<double> val(9);
13     for (int i = 0; i < 9; i++)
14     {
15         val[i] = PI * i*i;
16         cout << val[i] << endl;
17 
18     }
19 
20     valarray<double> valx(9);
21     for (int i = 0; i < 9; i++)
22     {
23         valx[i] = cos(i*PI / 3);
24         cout << valx[i] << endl;
25     }
26 
27     //拥有数组所有的功能
28     valarray<char *>my;
29     cin.get();
30 }