例4-2从键盘输入一批学生的成绩，立 四"G:1C语言课程\2010c. #include <stdio.h> Enter grades: -19869877855 void main() Grade average is 0 int num; Press any key to continue double grade,total; num 0;total =0; printf("Enter grades:In"); scanf(“%lf”,&grade);体输入第1个数* while(grade >=0) 输入负数，循环结束* { c四“G:1C语言课程12010Ck... total total grade; Enter grades: num++; 8987655367-1 Grade average is 72.20 scanf ("%lf",&grade); Press any key to continue if(num !0) printf("Grade average is %.2fn",total/num); else printf("Grade average is O\n"); 3例4-2 从键盘输入一批学生的成绩，计算平均分 #include <stdio.h> void main() { int num; double grade, total; num = 0; total = 0; printf(“Enter grades: \n"); scanf(“%lf”, &grade); /* 输入第1个数*/ while (grade >= 0) /* 输入负数，循环结束 */ { total = total + grade; num++; scanf (“%lf”, &grade); } if(num != 0) printf(“Grade average is %.2f\n", total/num); else printf(" Grade average is 0\n"); }