c语言程序，建立函数调用失败。

Question

题目：
建立学生信息档案，自建input（数据录入）和sort（数据排序）函数完成数据处理。
遇到的问题：
自建函数调用失败直接跳过了，原因不明。

# include<malloc.h>
# include<stdio.h>


struct Student
{
    int age;
    char name[100];
    float score;
};


void sort(int * lon, struct Student ** s)
{
    int i;
    int j;
    struct Student t;

    lon = (int *)malloc((*lon) * sizeof(struct Student));
    * s = (struct Student *)malloc((*lon)* sizeof(struct Student));    
    
    for(i=0; i<(*lon)-1; ++i)
        for(j=0; j<(*lon)-1-i; ++j)
            if((*s)[j].score < (*s)[j+1].score)
            {
                t = (*s)[j];
                (*s)[j] = (*s)[j+1];
                (*s)[j+1] = t;
            }
}


void Input(int *len, struct Student ** p)
{
    int i;
    len = (int *)malloc((*len) * sizeof(struct Student));
    * p = (struct Student *)malloc((*len) * sizeof(struct Student));        

    for(i=0; i<(*len); ++i)
    {
        printf("请输入第%d名学生信息\n", i+1);
        printf("name = ");
        scanf("%s", (*p)[i].name);
        printf("age = ");
        scanf("%d", &(*p)[i].age);
        printf("score = ");
        scanf("%f", &(*p)[i].score);    
    }
    return;
}


int main(void)
{
    int len;
    int i;
    struct Student * q;
    
    printf("请输入学生人数：\n");
    printf("len = ");
    scanf("%d", &len);

    Input (&len, &q);
    sort (&len, &q);

    for( i=0; i<len; ++i)
    {
        printf("第%d名学生的信息", i+1);
        printf("name = %s\n", q[i].name);
        printf("age = %d\n", q[i].age);
        printf("score = %f\n", q[i].score);
    }
    return 0;    
}

以下是执行结果：

请输入学生人数：
len = 3 （仅“3”为手动输入。）
第1名学生的信息Press any key to continue

Answer 1

修改如下 ：

# include<malloc.h>
# include<stdio.h>
 
struct Student
{
    int age;
    char name[100];
    float score;
};
 
void sort(int len, struct Student ** s)
{
    int i;
    int j;
    struct Student t;  
    for(i=0; i<len-1; ++i)
        for(j=0; j<len-1-i; ++j)
            if((*s)[j].score < (*s)[j+1].score)
            {
                t = (*s)[j];
                (*s)[j] = (*s)[j+1];
                (*s)[j+1] = t;
            }
}
 
void Input(int len, struct Student ** p)
{
    int i;    
    *p = (struct Student*)malloc(len * sizeof(struct Student)); 
    for(i=0; i<len; ++i)
    {
        printf("请输入第%d名学生信息\n", i+1);
        printf("name = ");
        scanf("%s", (*p)[i].name);
        printf("age = ");
        scanf("%d", &(*p)[i].age);
        printf("score = ");
        scanf("%f", &(*p)[i].score);    
    }
    return;
}
 
int main(void)
{
    int len;
    int i;
    struct Student * q = NULL;
    printf("请输入学生人数：\n");
    printf("len = ");
    scanf("%d", &len);
    Input (len, &q);
    sort (len, &q);
    for( i=0; i<len; ++i)
    {
        printf("第%d名学生的信息", i+1);
        printf("name = %s\n", q[i].name);
        printf("age = %d\n", q[i].age);
        printf("score = %f\n", q[i].score);
    }
    return 0;    
}