Professor Hopper is researching the sexual behavior of a rare species of bugs. He assumes that they feature two different genders and that they only interact with bugs of the opposite gender. In his experiment, individual bugs and their interactions were easy to identify, because numbers were printed on their backs.
Problem
Given a list of bug interactions, decide whether the experiment supports his assumption of two genders with no homosexual bugs or if it contains some bug interactions that falsify it.
2 3 3 1 2 2 3 1 3 4 2 1 2 3 4Sample Output
Scenario #1: Suspicious bugs found! Scenario #2: No suspicious bugs found!Hint
Huge input,scanf is recommended.
思路:这题比较好理解,用x+n来表示能与x交配的所有编号的虫子,如果发现两个互相交配的虫子AB同时可以交配同一个虫子C,那证明有homo虫。
#include <stdio.h>
int parent[2005+2005];
int find(int x)
{
return (x==parent[x])?x:parent[x]=find(parent[x]);
}
void init(int a)
{
for(int i=1;i<=2*a;i++)
parent[i]=i;
}
int same(int x,int y)
{
return find(x)==find(y);
}
void unite(int x,int y)
{
x=find(x);
y=find(y);
if(x==y) return ;
else parent[y]=x;
}
int main(void)
{
int t;
scanf("%d",&t);
for(int i=1;i<=t;i++)
{
int flag=0;
int amount,pair;
scanf("%d%d",&amount,&pair);
init(amount);
for(int i=1;i<=pair;i++)
{
int num1,num2;
scanf("%d%d",&num1,&num2);
if(same(num1,num2)==1)
flag=1;
else
unite(num1+amount,num2),unite(num1,num2+amount); // 关键
}
if(flag)
printf("Scenario #%d:\nSuspicious bugs found!\n\n",i);
else
printf("Scenario #%d:\nNo suspicious bugs found!\n\n",i);
}
}