| The three column Bandpass problem is solvable in linear time Recent countries visiting this post |  |
 | 5 | United States |
 | 3 | Russian Federation |
 | 1 | Sweden |
 | 1 |
| The three column Bandpass problem is solvable in linear time Recent countries visiting this post | |
| 5 | United States |
| 3 | Russian Federation |
| 1 | Sweden |
| 1 |