Na permutation algorithm
PLL (permute the last layer). Group: Corners and edges.
Na permutation: the top face is yellow all over. The algorithm swaps the front-left corner and the back-right corner, and swaps the left edge and the right edge.
The diagram shows the cube from above with the front at the bottom and yellow on top.
Algorithm
R U R' U R U R' F' R U R' U' R' F R2 U' R' U2 R U' R'
21 moves.
Other algorithms
F' R U R' U' R' F R2 F U' R' U' R U F' R'R F U' R' U R U F' R2 F' R U R U' R' Fr' D r U2 r' D r U2 r' D r U2 r' D r U2 r' D r
Source: www.speedsolving.com