EADST

Recently, I have done lots of LeetCode problems. Here are some quick shortcuts to change the list.

# initial one-dimensional array with length N
Array = [0] * N

# initial two-dimensional array with M*N
Matrix = [[0] * N for _ in range(M)]

# reverse the list [0, 1, 2]->[2, 1, 0]
new_list = old_list[::-1]
new_list = old_list.reverse()

# pop out the element in the list [0, 1, 2]->[0, 2]
new_list = old_list.pop(1)

# insert the element in the list [0, 1, 2]->[0, "s", 1, 2]
new_list = old_list.insert(1, "s")

# For a four-direction traversal, create an array [-1, 0, 1, 0, -1], each of which is one of the four directions.