1034. Head of a Gang (30)

分析：

　　考察并查集，注意中间合并时的时间的合并和人数的合并。

 #include <iostream>
 #include <stdio.h>
 #include <algorithm>
 #include <cstring>
 #include <string>
 #include <vector>
 #include <cctype>
 #include <map>

 using namespace std;

 const int Max_Int = 0x7fffffff;
 const int Max_required = ;

 struct Node                    //记录gang的信息
 {
     int total_person;        //gang中总人数
     int time_length;        //gang中总时间
     int tree;                //并查集用处
 }gang[];            

 struct Name
 {
     char ch[];
 };

 map<string, int> Map_Name2int;        //名字转下标之用
 map<int, string> Map_int2Name;
 int _index;

 int perp[];        //记录每个人花的时间

 void Init()
 {
     Map_Name2int.clear();
     _index = ;
     for (int i = ; i <= ; i++)
     {
         gang[i].total_person = ;
         gang[i].tree = i;
         gang[i].time_length = ;
         perp[i] = ;
     }
 }

 int string2index(string name)
 {
     map<string, int>::iterator iter = Map_Name2int.find(name);
     if (iter != Map_Name2int.end())
         return iter->second;
     Map_Name2int.insert(make_pair(name, _index));
     Map_int2Name.insert(make_pair(_index, name));
     _index++;

     return _index - ;
 }

 int get_root(int r)
 {
     while (r != gang[r].tree)
         r = gang[r].tree;
     return r;
 }

 //-------------------------------------------------
 void merge(int fir, int sec, int time)  //合并操作。
 {
     fir = get_root(fir);
     sec = get_root(sec);

     if (fir != sec)                    //如果两个拥有不同的根
     {
         gang[sec].tree = fir;
         gang[fir].time_length += time + gang[sec].time_length;
         gang[fir].total_person += gang[sec].total_person;
     }
     else
         gang[fir].time_length += time;
     //cout << gang[fir].total_person << " " << gang[fir].time_length << endl;
 }

 struct Gang                 //以root为首的群的head，存储答案
 {
     int head;
     int root;
     string name;
 }gang_head[];
 int total_gang;

 void find_head(int k)
 {
     total_gang = ;
     for (int i = ; i < _index; i++)
     {
         int r = get_root(i);

         //cout << r << " " << Map_int_Name.find(i)->second << endl;

         if (gang[r].total_person >  && gang[r].time_length > k)
         {
             bool flag = ;
             for (int j = ; j < total_gang; j++)
             {
                 if (gang_head[j].root == r)
                 {
                     flag = ;
                     if (perp[gang_head[j].head] < perp[i])
                         gang_head[j].head = i;
                     break;
                 }
             }

             if (flag == )
             {
                 gang_head[total_gang].head = i;
                 gang_head[total_gang].root = r;
                 total_gang++;
             }
         }
     }
 }

 int cmp(const Gang &a, const Gang &b)
 {
     return a.name < b.name;
 }

 void print_info()
 {
     for (int i = ; i < total_gang; i++)
         gang_head[i].name = Map_int2Name.find(gang_head[i].head)->second;

     sort(gang_head, gang_head + total_gang, cmp);

     printf("%d\n", total_gang);
     for (int i = ; i < total_gang; i++)
     {
         cout << gang_head[i].name << " " << gang[gang_head[i].root].total_person << endl;
     }

 }

 int main()
 {
     int n, k;

     while (scanf("%d%d", &n, &k) != EOF)
     {

         Init();                //初始化

         string name1, name2;
         int time;
         while (n--)
         {
             cin >> name1 >> name2 >> time;
             int fir = string2index(name1);
             int sec = string2index(name2);

             perp[fir] += time;
             perp[sec] += time;
             merge(fir, sec, time);
         } 

         find_head(k);

         print_info();
     }
     return ;
 }