| 110 | |
| 111 | // dfs1改成迭代版 |
| 112 | public static void dfs3(int cur, int father) { |
| 113 | stacksize = 0; |
| 114 | push(cur, father, 0, -1); |
| 115 | while (stacksize > 0) { |
| 116 | pop(); |
| 117 | if (e == -1) { |
| 118 | fa[u] = f; |
| 119 | dep[u] = dep[f] + 1; |
| 120 | siz[u] = 1; |
| 121 | e = head[u]; |
| 122 | } else { |
| 123 | e = nxt[e]; |
| 124 | } |
| 125 | if (e != 0) { |
| 126 | push(u, f, 0, e); |
| 127 | int v = to[e]; |
| 128 | if (v != f) { |
| 129 | push(v, u, 0, -1); |
| 130 | } |
| 131 | } else { |
| 132 | for (int ei = head[u]; ei > 0; ei = nxt[ei]) { |
| 133 | int v = to[ei]; |
| 134 | if (v != f) { |
| 135 | siz[u] += siz[v]; |
| 136 | if (son[u] == 0 || siz[son[u]] < siz[v]) { |
| 137 | son[u] = v; |
| 138 | } |
| 139 | } |
| 140 | } |
| 141 | } |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | // dfs2改成迭代版 |
| 146 | public static void dfs4(int cur, int tag) { |