[ 최소 신장 트리 ] 백준 1922번: 네트워크 연결 / 골드 4

https://www.acmicpc.net/problem/1922

1922번: 네트워크 연결

def find(parent, x):
    if parent[x] != x:
        parent[x] = find(parent, parent[x])
    return parent[x]

def union(parent, a, b):
    a = find(parent, a)
    b = find(parent, b)
    if a < b:
        parent[b] = a
    else:
        parent[a] = b

import sys
n = int(input())
m = int(input())
parent = [0]*(n+1)
edges = []
result = 0

for i in range(n+1):
    parent[i] = i

for _ in range(m):
    a, b, cost = map(int, sys.stdin.readline().split())
    edges.append([cost, a, b])

edges.sort()

for i in range(len(edges)):
    cost, a, b = edges[i]
    if find(parent, a) != find(parent, b):
        union(parent, a, b)
        result += cost

print(result)