UVA晚上活过来了,一看到这题就感觉是并查集的题,还真是,并查集找到一个最大的集合,然后
输出它的元素个数。
#include<stdio.h>
#include<string.h>
#define MAXD 30010
int p[MAXD], cnt[MAXD];
int n, m;
int find_set( int x)
{
return p[x] == x ? x : (p[x] = find_set(p[x]) );
}
void union_set( int x, int y)
{
x = find_set(x);
y = find_set(y);
if( x == y) return;
else {
p[y] = x;
cnt[x] += cnt[y];
}
}
int main()
{
int cas;
scanf( "%d", &cas);
while( cas --)
{
scanf( "%d%d", &n, &m);
for( int i = 1; i <= n; i ++)
{
p[i] = i;
cnt[i] = 1;
}
int a, b;
while( m --)
{
scanf( "%d%d", &a, &b);
union_set( a, b);
}
int max = 0;
for( int i = 1; i <= n; i ++)
if( cnt[i] > max)
max = cnt[i];
printf( "%d\n", max);
}
return 0;
}