【PY随笔】防忘记录

1. for循环的i的增加严格+1，需要变化的话得用while

2. 针对没有告诉具体结束次数，用try except

while True:
    try:
        n, m = map(int, input().split())
        stu = list(map(int, input().split()))
        stu.sort()
        num = 0
        i = 0
        ## for 循环内部完全不管你改变了顺序，继续在+1地做循环
        while i < n-1:
            if stu[i+1]-stu[i] < m:
                num = num + 1
                i = i + 2
            else:
                i = i + 1
        print(num)
    except:
        exit()

3. 字符串的左补0

m = '%0500d' % n 	# 500位，若不满则左补0

4. 输出全排列

import itertools
def strls(ls):
    s = ''
    for i in ls:
        s = s + i
    return s

n = int(input())
ls = list(input().split())				#得到一个列表
cls = list(itertools.permutations(ls))	#cls是ls全部排列的总列表集合（[]里有[]）
tmpls = strls(cls[0])
for i in cls:
    cur = strls(i)
    if cur > tmpls:
        tmpls = cur
print(tmpls)

5.四舍五入

print(str(int(jg/7*100+0.5)) + '%') # 四舍五入-》+0.5 后截断