valarray<T> cshift (int n) const;
Cyclically shift elements
Returns a valarray with its elements rotated left n spaces (or right if n is negative).
The valarray returned has the same length as *this.
By cyclically shifting (rotating) an array, the I-th element in the resulting valarray corresponds to the element with position (I+n)%size() in the original valarray.
Unlike with valarray::shift, the valarray returned by cshift does not initialize new elements with their default constructor to fill the
last n elements in *this (or the first -n elements if n is negative). Instead, it uses the first (or last) elements of *this.
Parameters
- n
- Number of elements to rotate. If positive, it is rotated left. If negative, it is rotated right.
Return value
A valarray object with the elements of *this rotated n spaces.
Example
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// valarray::cshift example
#include <iostream>
#include <valarray>
using namespace std;
int main ()
{
int init[]={10,20,30,40,50};
valarray<int> myvalarray (init,5); // 10 20 30 40 50
myvalarray = myvalarray.cshift(2); // 30 40 50 10 20
myvalarray = myvalarray.cshift(-1); // 20 30 40 50 10
for (size_t n=0; n<myvalarray.size(); n++)
cout << myvalarray[n] << ' ';
cout << endl;
return 0;
}
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Output:
See also
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