标签：style blog class code java c
题目描述
Jim is boss of a big company . There are so many workers in his company that it will take a long time for his command send to all of his workers . One day he want to know how long it will take at least . So he ask you , one of his best programer , to solve the problem . All the workers in Jim‘s conpany will receive command from only one people . So there is a tree (the root is Jim) identify the order Jim‘s command will send by . One send command to another will cost 1 minute and anyone can‘t send command to more than one people at the same time .
输入
There will be multiple cases in the input . For each case there will be just one number N (N<=10000) in the first line , then N-1 fellowed , each line with two names: worker1 worker2 , that is to say worker2 send command to worker1 . The name of the workers will only contain characters and the length is at most 5 .
输出
Just one number to tell how many minutes it will cost at least .
样例输入
5 Tom Jim Bob Jim John Tom Mily Tom
样例输出
3
唉！这个题一直做错，最后是在厚着脸皮问了学长，结果被学长狂虐了，树形dp，膜拜大神他们啊
#include<iostream> #include<cstdio> #include<map> #include<algorithm> #include<cstring> #include<string> #include<vector> using namespace std; vector<int>tree[10001]; map<string,int>people; typedef map<string,int>::iterator Itr; Itr itr; int nowmax; bool vis[10001]; bool cmp(int x,int y){return x>y;} int dfs(int u) { int a[10001]; int sum=tree[u].size(); if (sum==0) return 0; int ans=0,k=0; for (int i=0;i<tree[u].size();i++) { int v=tree[u][i]; if (!vis[v]) { vis[v]=true; a[++k]=dfs(v); } } sort(a+1,a+sum+1,cmp); for (int i=1;i<=sum;i++) ans=max(ans,a[i]+i); return ans; } int main() { int n,m; string str1,str2; m=0; while (scanf("%d",&n)!=EOF) { if (n==1) { cout<<"0"<<endl; continue; } for (int i=0;i<=n;i++) tree[i].clear(); m=0; people.clear(); for (int i=1;i<=n-1;i++) { cin>>str1>>str2; if(people.count(str1)==0) { people[str1]=++m; if (people.count(str2)==0) { people[str2]=++m; tree[m].push_back(m-1); } else tree[people[str2]].push_back(m); } else { if (people.count(str2)==0) { people[str2]=++m; tree[m].push_back(people[str1]); } else tree[people[str2]].push_back(people[str1]); } } int u=people["Jim"]; memset(vis,0,sizeof(vis)); vis[u]=true; cout<<dfs(u)<<endl; } return 0; }
毕竟是自己写的程序，加油
标签：style blog class code java c
原文地址：http://www.cnblogs.com/chensunrise/p/3721207.html
