강동연

def solution(n, results): answer = 0 arr = [[0 for _ in range(n + 1)] for _ in range(n + 1)] for x,y in results: arr[x][y] = 1 arr[y][x] = -1 for k in range(1, n+1): for i in range(1,n+1): for j in range(1, n+1): if arr[i][j] == 0 and arr[i][k] == arr[k][j] == 1: arr[i][j] = 1 elif arr[i][j] == 0 and arr[i][k] == arr[k][j] == -1: arr[i][j] = -1 for row in arr[1:]: # print(row) if row[1:].count(0) == 1: answer+=1 return answer print(solution(5, [[4, 3], [4, 2], [3, 2], [1, 2], [2, 5]]), 2)