未看视频前自己的实现，一些命名风格可能不一样

#[derive(Debug, Clone, PartialEq)]
enum Colour {
    Blue,
    Green,
    White
}

#[derive(Debug)]
pub struct BipartitionDetection {
    graph: Graph,
    visited: Vec<Colour>,
    is_bipartite: bool,
}

impl BipartitionDetection {
    pub fn new(graph: Graph) -> Self {
        let v = graph.v();
        let mut graph_dfs = Self {
            graph,
            visited: vec![White; v],
            is_bipartite: true
        };
        for v in 0..v {
            if graph_dfs.visited[v] == White {
                if !graph_dfs.dfs(v, v) {
                    graph_dfs.is_bipartite =  false;
                    break
                }
            }
        }
        graph_dfs
    }

    // 是否符合二分图规则
    fn dfs(&mut self, v: usize, parent: usize) -> bool {
        // 染色 颜色为父节点颜色的对立面
        let counter_color = match self.visited[parent] {
            Colour::Blue => {Colour::Green}
            Colour::Green => {Colour::Blue}
            White => {Colour::Blue}
        };
        self.visited[v] = counter_color;
        for w in self.graph.adj(v as i32).iter() {
            // 如果当前节点没有访问过则进行检测
            if self.visited[*w] == White {
                if !self.dfs(*w, v) {
                    return false;
                }
            } else {
                // 如果已经遍历过了查看颜色是否与当前节点是相对的
                if self.visited[*w] == self.visited[v] {
                    return false
                }
            }
        }
        true
    }

    pub fn is_bipartite(&self) -> bool {
        self.is_bipartite
    }
}