hdu 3172 Virtual Friends (并查集 + 字典树)

题目：

链接：点击打开链接

题意：

输入n，给出n行数据，每行有两个字符串，输出关系网络中朋友的个数，n行。

思路：

代码：

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;

const int N = 22;
const int M = 200020;

struct node
{
int c;
node *child[52];
node()
{
c = 0;
for(int i=0; i<52; i++)
child[i] = NULL;
}
}*root1;

int n;
int cnt;
int root[M];
char stra
,strb
;

int insertTrie(char s[])//字典树功能：将名字映射成代表该名字的一个整数
{
node *p = root1;
int len = strlen(s);
for(int k,i=0; i<len; i++,p=p->child[k])
{
if(s[i] >= 'a' && s[i] <= 'z')
k = s[i] - 'a';
else
k = s[i] - 'A' + 26;
if(!p->child[k])
p->child[k] = new node();
}
if(p->c)
return p->c;
return p->c = ++cnt;
}

void init()
{
for(int i=0; i<M; i++)
root[i] = -1;
}

int findset(int x)
{
int r;
for(r=x; root[r]>0; r=root[r]);
while(r != x)
{
int temp = root[x];
root[x] = r;
x = temp;
}
return r;
}

int mergeset(int r1,int r2)
{
int temp = root[r1] + root[r2];
if(root[r1] > root[r2])
{
root[r1] = r2;
root[r2] = temp;
}
else
{
root[r2] = r1;
root[r1] = temp;
}
return temp;
}

void dealTrie(node *p)
{
for(int i=0; i<52; i++)
{
if(p->child[i])
dealTrie(p->child[i]);
}
delete p;
p = NULL;
}

int main()
{
//freopen("input.txt","r",stdin);
int t;
while(scanf("%d",&t) != EOF)
{
while(t--)
{
scanf("%d",&n);
getchar();
cnt = 0;
init();
root1 = new node();
for(int i=0; i<n; i++)
{
scanf("%s%s",stra,strb);
int x = insertTrie(stra);
int y = insertTrie(strb);
int fx = findset(x);
int fy = findset(y);
if(fx != fy)
printf("%d\n",abs(mergeset(fx,fy)));
else
printf("%d\n",abs(root[fx]));
}
dealTrie(root1);
}
}
return 0;
}

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战斗，从不退缩；奋斗，永不停歇~~~~~~~~~~~~