[이코테] 그래프 이론_탑승구 (python)

문제

나의 풀이

1. 결국 뒷부분 풀이 봄

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

def union_parent(parent, a, b):
    a = find_parent(parent, a)
    b = find_parent(parent, b)
    if a < b:
        parent[b] = a
    else:
        parent[a] = b
        
d = int(input())
p = int(input())

parent = list(range(0, d + 1))
result = 0
for i in range(p):
    data = find_parent(parent, int(input()))
    if not data:
        break
    else:
        union_parent(parent, data, data - 1)
        result += 1
print(result)