51nod 1212 Graph-Free minimum spanning tree (Kruskal)

The undirected graph of the N-point M-edge, with a weighted value for each edge, to find the smallest spanning tree of the graph. Input

Line 1th: 2 number n,m The middle is separated by a space, N is the number of points, and M is the number of edges. (2 <= N <=, 1 <= M <= 50000)
2-m + 1 lines: 3 number s E W per line, respectively, representing 2 vertices and weights for M-bar edges. (1 <= S, E <= n,1 <= W <= 10000)

Output

Outputs the sum of weights for all edges of the minimum spanning tree.

Input example

9
1 2 4
2 3 8
3 4 7
4 5 9 5 6 6
7 2
7 8 1
8 9 7 2
8 each
3 9
2 7 9 6
  3 6 4
4 6
1 8 8

Output example

37

#include <iostream>
#include <algorithm>
#include <cstdio>
using namespace std;
int fa[1111];

void init (int n)
{for
	(int i=0;i<=n;i++) fa[i]=i;
}

int find (int x)
{
	int r;
	r=x;
	while (FA[R]!=R) r=fa[r];
	int i=x,j;
	while (i!=r) {
		j=fa[i];
		Fa[i]=r;
		i=j;
	}
	return r;
}
struct node
{
	int u;
	int V;
	int num;
} A[55555];

BOOL CMP (node X,node y)
{
	if (x.num<y.num) return true;
	return false;
}

int main ()
{
	 Ios::sync_with_stdio (false);  
	int I,j,n,m,ans;
	ans=0;
	cin>>n>>m;
	Init (n);
	for (i=0;i<m;i++) {
		cin>>a[i].u>>a[i].v>>a[i].num;
	}
	Sort (a,a+m,cmp);
	for (i=0;i<m;i++) {
		int fx=find (A[I].U);
		int Fy=find (A[I].V);
		if (fx!=fy) {
			fa[fx]=fy;
			Ans+=a[i].num;
		}
	}
	cout<<ans<<endl;
	return 0;
}