}intti,sn,top,n;intdfn[maxn];intlow[maxn];intins[maxn];intsta[maxn];intcol[maxn];intind[maxn];voidtarjan(intu) { dfn[u]=low[u]=++ti; ins[u]=1; sta[++top]=u;inti,k;for(i=head[u];i;i=e[i].next) { k=e[i].to;if(dfn[k]==0) { tarjan(k); low[u]=min(...
void add_edge(int v, int u) { G[cnt].to = u; G[cnt].next = head[v]; head[v] = cnt++; } void tarjan(int v) { dfn[v] = low[v] = index++; vis[v] = true; st[top++] = v; int u; for(int i = head[v]; i != -1; i = G[i].next) { u = G[i].to; i...
将那个入读为 0 的点从新图中删掉,再进行下一轮判断 如果当前的 DAG 中只剩一个节点,跳出拓扑排序过程,输出 Yes 缩点当然用 Tarjan 了 参考代码 POJ 2762 AC通道 POJ 2762 Going from u to v or from v to u?
void add(int u, int v) { edge[Ecnt].v=v; edge[Ecnt].next=head[u]; head[u]=Ecnt++; } void tarjan(int u) { low[u]=dfn[u]=++indx; instack[u]=1; stk[++top]=u; for(int i=head[u];i!=-1;i=edge[i].next){ int v=edge[i].v; if(!dfn[v]){ tarjan(v); low[...
POJ-2762 Going from u to v or from v to u?题目大意: 给出一个有向图,这个图,是否存在任意两点a,b可达,这里的任意两点a,b可达是说,只要从a能到b或者只要能从b到a就算是可达的。 解题思路: 先求出这个图的强连通分量,然后缩点建图,只要这个图是一条链状的,那么就可以满足任意两点都可达,否则不...
dd[u]=&pp[i]; qq[i].v=u; qq[i].next=rd[v]; rd[v]=&qq[i]; } } voiddfs(intk) { mark[k]=true; node*p=dd[k]; while(p) { if(!mark[p->v]) dfs(p->v); p=p->next; } cal[++ti]=k; } voidrdfs(intk)
poj 2672 Going from u to v or from v to u? 弱连通分量 Description In order to make their sons brave, Jiajia and Wind take them to a big cave. The cave has n rooms, and one-way corridors connecting some rooms. Each time, Wind choose two rooms x and y, and ask one of their ...
Whitney in west U.S. A 27-year-old female Chinese hiker, Dongying Qiu, went missing at Mt. Whitney, California in western U.S., since last Sunday. The rescuers are continuing to search for her and calling for all hikers to provide information. Oil prices keep rising ahead of OPEC ...
Next year I'm going to go to the United Kingdom to study. 翻译结果4复制译文编辑译文朗读译文返回顶部 I intend to learn to go to England next year. 翻译结果5复制译文编辑译文朗读译文返回顶部 I planned the next year will go to England to study. ...
1.因为点U出度为0,所以无法“出去”,它肯定无法到达V 2.因为点V出度为0,所以无法“出去”,它肯定无法到达U 3.综上,点U无法到达V,点V无法到达点U,与假设矛盾,所以与题目不成立 那么什么最后一个问题,如果这个DAG,入度为0的点的个数 <= 1 , 出度为0的点的个数 <= 1 , 它就一定Yes吗?