PAT 1001 A+B Format (20 分)

问题描述

Calculate a+b and output the sum in standard format – that is, the digits must be separated into groups of three by commas (unless there are less than four digits).

Input Specification:
Each input file contains one test case. Each case contains a pair of integers a and b where −10^​6 ≤ a, b≤10^6. The numbers are separated by a space.

Output Specification:
For each test case, you should output the sum of a and b in one line. The sum must be written in the standard format.

Sample Input:
-1000000 9
Sample Output:
-999,991

思路分析及代码实现

这道题的答题意思就是给你两个数，让你先求出这两个数之和，然后如果得到的结果每三个数一组，中间用逗号隔开，如果得到的结果是负数，则将负号放在第一组里

def solve(a, b):
    sum = a + b
    sum = list(str(sum))
    num = 0
    if sum[0] == '-':
        print('-', end='')
        sum = sum[1:len(sum)]
        n = len(sum)
        for i in range(len(sum)):
            print(sum[i],end='')
            num += 1
            if num % 3 == 0 and i != n - 1:
                print(',', end='')
                num = 0
    else:
        n = len(sum)
        for i in range(len(sum)):
            print(sum[i],end='')
            num += 1
            if num % 3 == 0 and i != n - 1:
                print(',', end='')
                num = 0


solve(-1000000, 9)