很简单的并查集
找父节点个数就是需要的桌子数
调试了好久是因为把find的while写成了if所以每次只查找一次父节点。
#include<iostream>
#include<cstdio>
#include<string.h>
using namespace std;
int n1, m;
struct node {
int fa;
};
node s[1001];
int sum[1001];
void sets()
{
for (int i = 0;i < n1;++i)
{
s[i].fa = i;
}
}
int find(int r)
{
int n=r;
while (n != s[n].fa)
{
n = s[n].fa;
}
int i = r, j;
while (i !=n )
{
j = s[i].fa;
s[i].fa = n;
i = j;
}
return n;
}
void join(int p1, int p2)
{
int x = find(p1);
int y = find(p2);
//printf("%d %d\n", x, y);
if (x != y)
{
s[x].fa = y;
}
}
int main(void)
{
int n;
scanf("%d", &n);
while (n-- > 0)
{
memset(sum, 0, sizeof(sum));
scanf("%d%d", &n1, &m);
sets();
while (m-- > 0)
{
int p1, p2;
scanf("%d%d", &p1, &p2);
join(p1-1, p2-1);
}
for (int i = 0;i < n1;++i)
{
int x = find(i);
//printf("%d\n", x);
sum[x] = 1;
}
int sum1=0;
for (int i = 0;i < n1;++i)
{
sum1 += sum[i];
}
cout << sum1 << endl;
}
}