| 93 | // 如果status == 1，表示u遍历到儿子v，然后发现dfn[v] != 0 |
| 94 | // 对应递归版for循环中的else分支 |
| 95 | public static void tarjan2(int node, int pree) { |
| 96 | stacksize = 0; |
| 97 | push(node, pree, -1, -1); |
| 98 | int v; |
| 99 | while (stacksize > 0) { |
| 100 | pop(); |
| 101 | if (status == -1) { |
| 102 | dfn[u] = low[u] = ++cntd; |
| 103 | e = head[u]; |
| 104 | } else { |
| 105 | v = to[e]; |
| 106 | if (status == 0) { |
| 107 | low[u] = Math.min(low[u], low[v]); |
| 108 | if (low[v] > dfn[u]) { |
| 109 | cutEdge[e >> 1] = true; |
| 110 | } |
| 111 | } else { |
| 112 | low[u] = Math.min(low[u], dfn[v]); |
| 113 | } |
| 114 | e = nxt[e]; |
| 115 | } |
| 116 | if ((e ^ 1) == preEdge) { |
| 117 | e = nxt[e]; |
| 118 | } |
| 119 | if (e != 0) { |
| 120 | v = to[e]; |
| 121 | if (dfn[v] == 0) { |
| 122 | push(u, preEdge, 0, e); |
| 123 | push(v, e, -1, -1); |
| 124 | } else { |
| 125 | push(u, preEdge, 1, e); |
| 126 | } |
| 127 | } |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | public static void main(String[] args) throws Exception { |
| 132 | FastReader in = new FastReader(System.in); |