zoukankan      html  css  js  c++  java
  • Circles of Friends

    A circle of friends is a network of friend relationships. If A is a friend of B, then B is considered a friend of A no matter B admits or not, and they are said to belong to the same circle. Here we assume that friendship is transitive, that is, if A is a friend of B, and B is a friend of C, then A is a friend of C and the three of them all belong to the same circle.

    On the other hand, A is not so close to C as B is. We define the distance D(X, Y) between two friends X and Y as the minimum number of friends between them. For example, D(A, B) = 0, and D(C, A) = 1. The diameter of a friends circle is the maximum distance between any pair of friends in the circle.

    Now given some people's relationships, you are supposed to find the number of friends circles and the circle with the largest diameter.

    Input Specification:

    Each input file contains one test case. For each case, the first line gives an integer N (2), which is the total number of people involved, and hence they are numbered from 1 to N. Then N lines follow, each in the format:

    p1​​ ... pk​​

    where k (0) is the number of friends and p1​​ to pk​​ (if k>0) are the friends' indices. The i-th line corresponds to the i-th person. All the numbers in a line are separated by spaces. It is guaranteed that no one is given as a friend of oneself.

    Output Specification:

    For each case, print in a line the number of friends circles, and the largest diameter, separated by exactly one space.

    Sample Input:

    17
    2 15 12
    1 17
    2 16 9
    1 8
    4 10 13 15 14
    0
    2 11 14
    1 4
    2 2 3
    2 13 11
    2 15 7
    2 1 14
    2 5 15
    0
    0
    1 3
    1 2
    
     

    Sample Output:

    4 3
     1 #include<bits/stdc++.h>
     2 using namespace std;
     3 vector<set<int> > v;
     4 vector<bool> vb;
     5 vector<int> vr;
     6 set<int>::iterator its;
     7 int spart,smax;
     8 void bfs(int n,bool flag)
     9 {
    10     vector<bool> vbb(vb.size(),true);
    11     int md=0;
    12     pair<int,int> p;
    13     queue<pair<int,int> > q;
    14     q.push(pair<int,int>(n,-1));
    15     if(flag)
    16     vb[n]=false;
    17     else
    18     vbb[n]=false;
    19     for(;!q.empty();q.pop())
    20     {
    21         p=q.front();
    22         if(p.second>md)
    23         {
    24             md=p.second;
    25             if(flag)
    26             {
    27                 vr.clear();
    28                 vr.push_back(p.first);
    29             }
    30         }
    31         else if(p.second==md)
    32         if(flag)
    33         vr.push_back(p.first);
    34         for(its=v[p.first].begin();its!=v[p.first].end();++its)
    35         {
    36             if(flag)
    37             {
    38                 if(vb[*its])
    39                 {
    40                     vb[*its]=false;
    41                     q.push(pair<int,int>(*its,p.second+1));
    42                 }
    43             }
    44             else
    45             {
    46                 if(vbb[*its])
    47                 {
    48                     vbb[*its]=false;
    49                     q.push(pair<int,int>(*its,p.second+1));
    50                 }
    51             }
    52         }
    53     }
    54     if(md>smax)
    55     smax=md;
    56     return;
    57 }
    58 int main()
    59 {
    60 //    ios::sync_with_stdio(false);
    61  //     freopen("data.txt","r",stdin);
    62       int n,k,x;
    63       spart=0,smax=0;
    64       scanf("%d",&n);
    65       v.resize(n);
    66       vb.resize(n,true);
    67       for(int i=0;i<n;i++)
    68       {
    69           scanf("%d",&k);
    70           for(;k--;)
    71           {
    72               scanf("%d",&x);
    73               x--;
    74             v[i].insert(x);
    75             v[x].insert(i);
    76         }
    77     }
    78     for(int t=0;t<v.size();t++)
    79     {
    80         if(vb[t])
    81         {
    82             bfs(t,true);
    83             for(int i=0;i<vr.size();i++)
    84             bfs(vr[i],false);
    85             spart++;
    86             t=0;
    87         }
    88     }
    89     printf("%d %d",spart,smax);
    90 
    91     return 0;
    92 }
    诚者,君子之所守也。
  • 相关阅读:
    2.5(他们其实都是图)
    食物链POJ1182
    LG P6748 『MdOI R3』Fallen Lord
    LG P4199 万径人踪灭
    LG P1912 [NOI2009]诗人小G
    LG P4381 [IOI2008]Island
    2020/8/9 模拟赛 T3 表格
    UOJ422 【集训队作业2018】小Z的礼物
    CF913F Strongly Connected Tournament
    LG P5643 [PKUWC2018]随机游走
  • 原文地址:https://www.cnblogs.com/SkystarX/p/12285794.html
Copyright © 2011-2022 走看看