搭建自己的博客网站,做网站推广书范法吗,jsp网站开发小程序,泊头网站建设服务思路#xff1a;将以桥为分界的所有连通分支进行缩点#xff0c;得到一颗树#xff0c;求出树的直径。再用树上的点减去直径#xff0c;再减一 #pragma comment(linker, /STACK:1024000000,1024000000) #includeiostream #includecstdio #incl…思路将以桥为分界的所有连通分支进行缩点得到一颗树求出树的直径。再用树上的点减去直径再减一 #pragma comment(linker, /STACK:1024000000,1024000000) #includeiostream #includecstdio #includecstring #includealgorithm #includemap #includequeue #define Maxn 210110 #define Maxm 2501000 using namespace std; int index[Maxn],vi[Maxn],dfn[Maxn],low[Maxn],e,n,lab0,Stack[Maxn],top,num,head[Maxn],ans,id[Maxn]; void init() {memset(index,-1,sizeof(index));memset(head,-1,sizeof(head));memset(vi,0,sizeof(vi));memset(low,0,sizeof(low));memset(dfn,0,sizeof(dfn));elabtopnumans0; } struct Edge{int from,to,next,v; }edge[Maxm]; void addedge(int from, int to) {edge[e].v0;edge[e].fromfrom;edge[e].toto;edge[e].nextindex[from];index[from]e;edge[e].v0;edge[e].tofrom;edge[e].fromto;edge[e].nextindex[to];index[to]e; } void add(int from,int to) {edge[e].v0;edge[e].fromfrom;edge[e].toto;edge[e].nexthead[from];head[from]e;edge[e].v0;edge[e].tofrom;edge[e].fromto;edge[e].nexthead[to];head[to]e; } int Count(int u) {num;int i;do{//将该连通分量进行标记iStack[--top];id[i]num;}while(i!u);return 0; } int dfs(int u) {dfn[u]low[u]lab;Stack[top]u;int i,j,temp;for(iindex[u];i!-1;iedge[i].next){tempedge[i].to;if(edge[i].v) continue;//一开始没加这个判断,一直WAedge[i].vedge[i^1].v1;if(!dfn[temp]){dfs(temp);low[u]min(low[u],low[temp]);}low[u]min(low[u],dfn[temp]);}if(dfn[u]low[u])Count(u);return 0; } int maxLen(int u) {vi[u]1;int i,j,temp0,Max0,lMax0;for(ihead[u];i!-1;iedge[i].next){if(!vi[edge[i].to]){tempmaxLen(edge[i].to);if(temp1Max){lMaxMax;Maxtemp1;}else{if(temp1lMax)lMaxtemp1;}if(MaxlMaxans)ansMaxlMax;}}return Max; } int solve() {int i,j,u,v,ed;dfs(1);ede;e0;for(i0;ied;i2){uid[edge[i].from];vid[edge[i].to];add(u,v);}memset(vi,0,sizeof(vi));ans0;maxLen(1);return num-1-ans; } int main() {int m,i,j,a,b;while(scanf(%d%d,n,m),n||m){init();for(i1;im;i){scanf(%d%d,a,b);addedge(a,b);}printf(%d\n,solve());}return 0; }    转载于:https://www.cnblogs.com/wangfang20/p/3215313.html