zoukankan      html  css  js  c++  java
  • The Suspects(并查集求节点数)

    The Suspects
    Time Limit: 1000MS   Memory Limit: 20000K
    Total Submissions: 28164   Accepted: 13718

    Description

    Severe acute respiratory syndrome (SARS), an atypical pneumonia of unknown aetiology, was recognized as a global threat in mid-March 2003. To minimize transmission to others, the best strategy is to separate the suspects from others. 
    In the Not-Spreading-Your-Sickness University (NSYSU), there are many student groups. Students in the same group intercommunicate with each other frequently, and a student may join several groups. To prevent the possible transmissions of SARS, the NSYSU collects the member lists of all student groups, and makes the following rule in their standard operation procedure (SOP). 
    Once a member in a group is a suspect, all members in the group are suspects. 
    However, they find that it is not easy to identify all the suspects when a student is recognized as a suspect. Your job is to write a program which finds all the suspects.

    Input

    The input file contains several cases. Each test case begins with two integers n and m in a line, where n is the number of students, and m is the number of groups. You may assume that 0 < n <= 30000 and 0 <= m <= 500. Every student is numbered by a unique integer between 0 and n−1, and initially student 0 is recognized as a suspect in all the cases. This line is followed by m member lists of the groups, one line per group. Each line begins with an integer k by itself representing the number of members in the group. Following the number of members, there are k integers representing the students in this group. All the integers in a line are separated by at least one space. 
    A case with n = 0 and m = 0 indicates the end of the input, and need not be processed.

    Output

    For each case, output the number of suspects in one line.

    Sample Input

    100 4
    2 1 2
    5 10 13 11 12 14
    2 0 1
    2 99 2
    200 2
    1 5
    5 1 2 3 4 5
    1 0
    0 0

    Sample Output

    4
    1
    1
    代码:
     1 #include<stdio.h>
     2 #include<string.h>
     3 const int MAXN=30010;
     4 int pre[MAXN],num[MAXN];
     5 int find(int x){
     6     return pre[x]=x==pre[x]?x:find(pre[x]);
     7 }
     8 int merge(int x,int y){
     9     int f1,f2;
    10     f1=find(x);f2=find(y);
    11     if(f1!=f2){
    12         if(f1<f2)pre[f2]=f1,num[f1]+=num[f2];
    13         else pre[f1]=f2,num[f2]+=num[f1];
    14     }
    15 }
    16 int main(){
    17     int n,m,k,a,b;
    18     while(scanf("%d%d",&n,&m),n|m){
    19         for(int i=0;i<n;i++){
    20             pre[i]=i;
    21             num[i]=1;
    22         }
    23         while(m--){
    24             scanf("%d",&k);
    25             scanf("%d",&a);
    26             for(int i=1;i<k;i++){
    27                 scanf("%d",&b);
    28                 merge(a,b);
    29             }
    30         }
    31         printf("%d
    ",num[0]);
    32     }
    33     return 0;
    34 }
  • 相关阅读:
    数据库操作,内外联查询,分组查询,嵌套查询,交叉查询,多表查询,语句小结
    重复控件Repeater和数据列表控件DataList
    网格视图控件GridView (2)
    用好VS2005之扩展membership服务(1)
    5.4 网格视图控件GridView (1)
    数据源控件
    ASP.NET程序中常用的三十三种代码
    在DataSet和DataReader之间选择
    自定义ASP.net 2.0 Membership的步骤,和entry 'AspNetSqlMembershipProvider' has already been added错误的解决
    INNER JOIN
  • 原文地址:https://www.cnblogs.com/handsomecui/p/4822322.html
Copyright © 2011-2022 走看看