Function build_knight_graph

code/chapter08/kinght_tour.rs:115–135

构建可移动路径图

(bdsize: u32)

// 构建可移动路径图
fn build_knight_graph(bdsize: u32) -> Graph<u32> {
    // 闭包函数，计算点值 [0, 63]
    let calc_point = |row: u32, col: u32, size: u32| {
        (row % size) * size + col
    };

    // 各点间设置边
    let mut knight_graph = Graph::new();
    for row in 0..bdsize {
        for col in 0..bdsize {
            let dests = legal_moves(row, col, bdsize);
            for des in dests {
                let src_p = calc_point(row, col, bdsize);
                let des_p = calc_point(des.0, des.1, bdsize);
                knight_graph.add_edge(&src_p, &des_p);
            }
        }
    }

    knight_graph
}

// depth: 走过的路径长度, curr: 当前节点, path: 保存访问过的点
fn knight_tour<T>(