#includeint main(){float std[100],sum=0;int i=0,num;printf("输入学生成绩，以-1结束:");for(;i<100;i++){scanf("%f",&std[i]);if(std[i] == -1) break;}num = i;for(i=0;isum = sum/num;printf("学生的平均成绩是%f",sum);return 0;}
