Uva315-network (non-direction graph cut point)

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Test Instructions: The number of cut points is given by a graph without direction .

Ideas: very naked topic, direct template can be.

code:

#include <iostream> #include <cstdio> #include <cstring> #include <algorithm>using namespace    std;const int MAXN = 1005;struct edge{int to, next; bool Cut;}    EDGE[MAXN * 10];int HEAD[MAXN], Tot;int LOW[MAXN], dfn[maxn];int Index, Cnt;bool cut[maxn];void addedge (int u, int v) {    Edge[tot].to = v;    Edge[tot].next = Head[u];    Edge[tot].cut = false; Head[u] = tot++;}    void Tarjan (int u, int pre) {int V;    Low[u] = dfn[u] = ++index;    int son = 0;        for (int i = head[u]; I! =-1; i = edge[i].next) {v = edge[i].to;         if (v = = pre) continue; if (!             Dfn[v]) {son++;             Tarjan (V, u);            if (Low[u] > Low[v]) low[u] = Low[v];             if (u! = Pre && low[v] >= Dfn[u]) {Cut[u] = true;    }} else if (Low[u] > Dfn[v]) low[u] = Dfn[v]; } if (U = = Pre && son > 1) cut[u] = true;}    void Init () {memset (head,-1, sizeof (head));memset (DFN, 0, sizeof (DFN));     Memset (cut, false, sizeof (cut));    tot = 0; Index = CNT = 0;}     int main () {int n;         while (scanf ("%d", &n) && N) {init ();        int u, v;            while (scanf ("%d", &u) && u) {char ch;                 while (scanf ("%d%c", &v, &ch)) {Addedge (U, v);                 Addedge (V, u);            if (ch = = ' \ n ') break; }} for (int i = 1; I <= n; i++) if (!        Dfn[i]) Tarjan (i, I);        for (int i = 1; I <= n; i++) if (cut[i]) cnt++;    printf ("%d\n", CNT); } return 0;}

Uva315-network (non-direction graph cut point)