1 num =1
2 sum =0 3 while num <=99: 4 if num % 2 ==1: 5 sum = sum + num 6 num =num +1
7 print(sum)
2.求1-2+3-4+5...99的所有数的和
1 num =1
2 sum =0 3 while num <=99: 4 if num % 2 ==1: 5 sum = sum + num 6 else: 7 sum =sum -num 8 num =num +1
9 print(sum)