I/O

New-Coder Input

牛客网上面刷题时可能用到的多组输入输出：

• 输入 m, n 两个数：

str_in = input()
m, n = [int(_) for _ in str_in.split()]

• 多组输入，第一行 n 表示数的数量，第二行输入这 n 个数：

n, m = input(), list(map(int, input().split()))

• 输入有多组数据：

import sys

s = sys.stdin.readline().strip()
if not s:
    break

Format Output

When output, we can use str(), repr() and print(), the different between them could be found in Python3 Tutorial.

The usage of format , one thing to note :

print('{0} and {1}'.format('Google', 'Baidu'))
>>> Google and Baidu
print('{1} and {0}'.format('Google', 'Baidu'))
>>> Baidu and Google

print(f'some string')
# raw string

print('{0:2d} {1:3f}'.format(1,2))
# specifies the length of the placeholder

print('{name}: age}'.format(name = 'weigao', age = '18'))
>>> weigao: 18

The % also can be use to format output, but it is an old way, so use it as little as possible.

Input

Python provides the input() function from the standard input to a line, and the default standard input is the keyboard.

str = input("please input: ")
print("your input is: ", str)

In Newcoder programming test, somethings we need custom input, there are some ways for us to reference:

• Mutil input and output

例如第一行表示接下来要输入的行数，接下来若干行输入，并且涉及多组输入输出时：

while True:
    try:
        n = int(input())
        lists = [int(input()) for _ in range(n)]
        # the code
    except:
        break