オセロゲームなどで自分のコマの周りがどうなっているかを取得する

    fn live_neighbor_count(&self, row: u32, column: u32) -> u8 {
        let mut count = 0;
        for delta_row in [self.height - 1, 0, 1].iter().cloned() {
            for delta_col in [self.width - 1, 0, 1].iter().cloned() {
                if delta_row == 0 && delta_col == 0 {
                    continue;
                }

                let neighbor_row = (row + delta_row) % self.height;
                let neighbor_col = (column + delta_col) % self.width;
                let idx = self.get_index(neighbor_row, neighbor_col);
                count += self.cells[idx] as u8;
            }
        }
        count
    }

fn live_neighbor_count(&self, row: u32, column: u32) -> u8 {
    let mut count = 0;

    let north = if row == 0 {
        self.height - 1
    } else {
        row - 1
    };

    let south = if row == self.height - 1 {
        0
    } else {
        row + 1
    };

    let west = if column == 0 {
        self.width - 1
    } else {
        column - 1
    };

    let east = if column == self.width - 1 {
        0
    } else {
        column + 1
    };

    let nw = self.get_index(north, west);
    count += self.cells[nw] as u8;

    let n = self.get_index(north, column);
    count += self.cells[n] as u8;

    let ne = self.get_index(north, east);
    count += self.cells[ne] as u8;

    let w = self.get_index(row, west);
    count += self.cells[w] as u8;

    let e = self.get_index(row, east);
    count += self.cells[e] as u8;

    let sw = self.get_index(south, west);
    count += self.cells[sw] as u8;

    let s = self.get_index(south, column);
    count += self.cells[s] as u8;

    let se = self.get_index(south, east);
    count += self.cells[se] as u8;

    count
}