(int cur)
| 78 | |
| 79 | // 迭代版 |
| 80 | public static void dfs2(int cur) { |
| 81 | stacksize = 0; |
| 82 | push(cur, -1, 0, -1); |
| 83 | int v; |
| 84 | while (stacksize > 0) { |
| 85 | pop(); |
| 86 | if (status == -1) { |
| 87 | dfn[u] = ++cntd; |
| 88 | e = head[u]; |
| 89 | } else { |
| 90 | v = to[e]; |
| 91 | if (status == 1 && dfn[u] < dfn[v]) { |
| 92 | x = u; |
| 93 | y = v; |
| 94 | skip = (e + 1) >> 1; |
| 95 | } |
| 96 | e = nxt[e]; |
| 97 | } |
| 98 | if (e != 0) { |
| 99 | v = to[e]; |
| 100 | if (dfn[v] == 0) { |
| 101 | push(u, 0, 0, e); |
| 102 | push(v, -1, 0, -1); |
| 103 | } else { |
| 104 | push(u, 1, 0, e); |
| 105 | } |
| 106 | } |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | // 递归版 |
| 111 | public static void dpOnTree1(int u, int fa) { |