c语言 char输出问题,实在找不出来问题

#include
#define N 3
struct Student{
int number;
int age;
char sex;
char name[20];
float english;
float math;
float computer;
float aver;
};
void main(){

struct Student stu[N];
struct Student  *p;
p=stu;
void  input(struct Student stu[]);
struct Student max(struct  Student  stu[]);
void  print(struct Student stu);  
input(p);
print(max(p));

}
void input(struct Student stu[]){

for(int i=0;i<N-1;i++){
printf("please  input  number:\n");
scanf("%d",&stu[i].number);
printf("please  input  age:\n");
scanf("%d",&stu[i].age);
printf("please  input name:\n");
scanf("%s",stu[i].name);
printf("please  input sex:\n");
scanf("%c",&stu[i].sex);
printf("please  input score:\n");
scanf("%f,%f,%f",&stu[i].english,&stu[i].math,&stu[i].computer);


stu[i].aver=(stu[i].english+stu[i].math+stu[i].computer)/3.0;

}

}
struct Student max(struct Student stu[]){
struct Student temp1;
temp1=stu[0];
for(int i=0;i <N-1;i ++){
if(stu[i].aver<stu[i+1].aver)
temp1=stu[i+1];
}
return temp1;
}
void print(struct Student stu){
printf("number:%d age:%d sex:%c name:%s \n"
"english:%f math:%f computer:%f ",stu.number,stu.age,stu.sex,stu.name,stu.english,stu.math,stu.computer);

}

为什么输入age时就跳过了,改了几次改为printf("please input sex:\n");
scanf("%s",&stu[i].sex); 却能输入 了,但输出时name值没了

因为上一句scanf("%s",stu[i].name)缓冲区中的'\n'并没有被取走,所以scanf("%c",&stu[i].sex)实际读到的是'\n'

已经解决了,改写为scanf(" %c",&stu[i].sex);百分号前面加个空格
或者 在这句前加一句 getchar();

但我还是不懂原因,求大神告知原因,有说是缓存区垃圾,求详解