算了下复杂度好像是n^3 就感觉不大好做。结果n^31a。。。
#include <cstdio> #include <algorithm> #include <iostream> #include <string.h> #include <map> #include <vector> #include <string> #include <queue> using namespace std; #define eps 1e-9 #define PI acos(-1.0) #define N 1005 #define inf 10000000 map<string,int>mp; vector<int>G[N*2]; vector<string>ans; int Stack[N*2],topans; int n, m; char s[N*2][20], tmp[2][20]; int vis[N*2]; bool bfs(int u){ memset(vis,0,sizeof vis); vis[u] = -1; queue<int>q; for(int i = 0; i < G[u].size(); i++)q.push(G[u][i]),vis[G[u][i]]=-1; int siz = -2; while(!q.empty()){ u = q.front(); q.pop(); for(int i = 0; i < G[u].size(); i++){ int v = G[u][i]; if(vis[v]==-1)continue; vis[v]++; if(siz<vis[v]){siz = vis[v];topans = 1;Stack[0] = v;} else if(siz==vis[v]){Stack[topans++] = v;} } } if(siz<0)return false; ans.clear(); for(int i = 0; i < topans; i++)ans.push_back(s[Stack[i]]); sort(ans.begin(), ans.end()); for(int i = 0; i < ans.size();i++){cout << ans[i];i==ans.size()-1?puts(""):printf(" ");} return true; } int main() { int T, Cas = 1, i, j; scanf("%d",&T); while(T--){ mp.clear(); scanf("%d %d",&n,&m); for(i = 1; i <= 2*n; i++)G[i].clear(); int top = 0; while(n--) { scanf("%s %s",tmp[0],tmp[1]); if(mp.find(tmp[0])==mp.end()){ mp[tmp[0]] = ++top; memcpy(s[top],tmp[0],sizeof tmp[0]); i = top; } else i = mp.find(tmp[0])->second; if(mp.find(tmp[1])==mp.end()){ mp[tmp[1]] = ++top; memcpy(s[top],tmp[1],sizeof tmp[1]); j = top; } else j = mp.find(tmp[1])->second; G[i].push_back(j);G[j].push_back(i); } printf("Case %d:\n",Cas++); while(m--) { scanf("%s",tmp[0]); i = mp.find(tmp[0])->second; if(bfs(i)==false)puts("-"); } } return 0; }
HDU 4039 The Social Network bfs,布布扣,bubuko.com
HDU 4039 The Social Network bfs
原文地址:http://blog.csdn.net/acmmmm/article/details/25790405