南理工 C++ 课后 习题答案 第二章 1. 选择题 (1) C (2) ABC (3)D (4)BC (5)A (6)A (7)D (8)B (9)A 2. 填空题 (1) 22 (2) 2 (3) 1 (4) 1 0 1 (5) float (6) double (7) 1 (8) 1 (9)a = n%10 b = n/10%10 c = n/100%10 d = n/1000 (10) (a)sin(x)/(x-y) (b) sqrt(s*(s-a)*(s-b)*(s-c)) (c)(a-b)*(a+b) (d) (x+y)/fabs(x-y)