例题一块9×9的方格布上分布着一些霉菌。任一格子,如果与其存在公共边的格子中,有两个或两个以上含有霉菌,那么它自身也将逐渐被霉菌感染,否则便不会。若要使所有格子最终都感染上霉菌,那么起初至少需要几个带霉菌的格子?分析与解试想,如果霉菌起初位于对角线上的9个方格中,便可顺利传染到整块方格布。但9是最少的情况吗?我们可以去证明一下。 Example A piece of 9 × 9 checkered cloth is distributed with some mold. Any grid, if there are two or more molds in the grid with its common side, will itself become infected with the mold itself, otherwise it will not. If at least some molds are to be initially infected with molds at a time, then at least a few molds are needed. Analysis and Interpretation Imagine that if the mold was originally in nine diagonals, Gebu. But is 9 the least? We can prove it.