C语言程序设计习题与上机实验(实验答案)

第三部分 上机实验与指导(答案) 实验三 选择结构程序设计 1、 main() { float score; char grade; printf(“Please input a student’ score:”); scanf(“%f”, &score); while(score>100 || score<0) { printf(“\nInput error, try again!”); scanf(“%f”, &score); } switch ( (int)(score/10) ) { case 10: case 9: grade=’A’; break; case 8: grade=’B’; break; case 7: grade=’C’; break; case 6: grade=’D’; break; case 5: case 4: case 3: case 2: case 1: case 0: grade=’E’; } printf(“score is %5.1f, score grade is %c.\n”, score, grade); } 2、 #include main( ) { float x, y ; printf(“Please input x:”); scanf(“%f”, &x); if (x < 0) y = 0; else if (x < 10) y = x ; else if ( x < 20 ) y = 10; else if ( x < 40) y = 0.5 * x + 20; else { printf(“Input Error!”); exit (0); } printf (“y=%g”, y); } 3、 include void main(void) { int choice; /* 显示菜单及输入提示信息 */ printf("----------------------------------------------- \n") ; printf(" The Menu of Data Management \n") ; printf(" 1. Input Data \n") ; printf(" 2. Output Data \n") ; printf(" 3. Insert Data \n") ; printf(" 4. Delete Data \n") ; printf(" 0. Quit System \n") ; printf("----------------------------------------------- \n") ; printf(" Please enter your choice： \n") ; /* 接收从键盘输入的数；*/ scanf("%d", &choice); /* 根据输入数据显示不同信息 */ switch (choice) { case 1: printf("Input Data ") ; break; case 2: printf("Output Data ") ; break; case 3: printf("Insert Data ") ; break; case 4: printf("Delete Data ") ; break; case 0: printf("Thanks!"); break; default: printf("Input Error! ");exit(0); } } 实验四 循环结构程序设计 1、 #include main( ) { char ch; int i; for (i=0; i<10;i++); { ch = getchar(); if (ch >= ‘a’ && ch <...