POJ 3352-side Double Unicom

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Test instructions: The topic is very long does not say, is to seek to add a few sides, arbitrarily delete an edge, the figure or Unicom

Idea: the definition of the side double Unicom component is to delete a side after the diagram is still connected, here is recommended this article is written in detail here, and this is the recommendation of the article in the construction of double-link diagram of the bridge method, then we directly quoted, proof to see that article, for a unicom map, we find all the bridge, the method of bridge is to find the low and DFS array complete, my code is the L and e arrays, the bridge after the deletion of the diagram is definitely a plurality of unicom blocks, and each block is definitely a double-link sub-map, which is defined by the bridge can be seen, and then each piece is shrunk to a point, connected to find a degree of 1 points of the number +1 and 2 is the result, The recommended article has proof

#include <vector> #include <stdio.h> #include <stdlib.h> #include <string.h> #include < Iostream> #include <algorithm>using namespace std;typedef long long ll;const int Inf=0x3f3f3f3f;const int maxn= 1050;vector<int>g[maxn];int l[maxn],cnt[maxn],vis[maxn];int n,m,k;void dfs (int x,int fa) {vis[x]=1;    l[x]=k++;        for (unsigned int i=0;i<g[x].size (); i++) {int t=g[x][i];        if (T==FA) continue;        if (!vis[t]) DFS (T,X);    L[x]=min (L[x],l[t]);    }}int Tarjan () {K=0;dfs ();            for (int i=1;i<=n;i++) {for (unsigned int j=0;j<g[i].size (); j + +) {int t=g[i][j];            if (L[i]!=l[t]) {cnt[l[i]]++;    }}} int ans=0;    for (int i=1;i<=n;i++) {if (cnt[i]==1) ans++; } return (ans+1)/2;}    int V[maxn][maxn];int Main () {int a A, B;        while (scanf ("%d%d", &n,&m)!=-1) {for (int i=0;i<maxn;i++) {g[i].clear (); cnt[i]=0; } memset (viS,0,sizeof (VIS));            for (int i=0;i<m;i++) {scanf ("%d%d", &a,&b);            G[a].push_back (b);        G[b].push_back (a);        } int Ans=tarjan ();    printf ("%d\n", ans); } return 0;}

POJ 3352-side Double Unicom