hdu 1181 变形课

题目链接

discuss里面都是dfs为主的，我就写了一个并查集，就是有向需要注意下。#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<algorithm>
#include<math.h>
using namespace std;
#define LL long long
int father[1007];
int find(int x)
{
while(x!=father[x])
x=father[x];
return x;
}
main()
{
char word[999];
int i;

while(scanf("%s",&word)!=EOF)
{
for(i=0;i<=29;i++)
father[i]=i;
int a=word[0]-'a',b=word[strlen(word)-1]-'a';
if(a!=b && b!='b'-'a')
if(find(a)!=find(b))
father[b]=find(a);
while(scanf("%s",&word)!=EOF && word[0]!='0')
{
int a=word[0]-'a',b=word[strlen(word)-1]-'a';
if(a!=b && b!='b'-'a')
if(find(a)!=find(b))
father[b]=find(a);
}
if(find('m'-'a')==find('b'-'a'))
printf("Yes.\n");
else printf("No.\n");
}

}