http://codeup.kr/problem.php?id=1472
Codeup 1472 - [기초-배열연습] 2차원 배열 지그재그 채우기 2-5
n, m = map(int, input().split())
matrix = [[0]*m for i in range(n)]
cnt = 0
for i in range(0, n):
index = n - i - 1
if i % 2:
for j in range(0, m):
cnt += 1
matrix[index][j] = cnt
else:
for j in range(m-1, -1, -1):
cnt += 1
matrix[index][j] = cnt
for i in range(0, n):
for j in range(0, m):
print(matrix[i][j], end=' ')
print()