13 views
Coins are situated on an $m \times m$ board. Each coin situated on the board is said to dominate all the cells of the row $(\rightarrow)$, the column $(\downarrow)$, and the diagonal $(>)$ ). Note that the coin does not dominate the diagonal ( ). Determine the smallest number of coins which must be placed in order that all the cells of the board be dominated.
| 13 views