来自外部编译器的新图片..退出代码可以吗？
这是完整的代码。在将所需输出打印到屏幕后，我遇到麻烦程序。我想这是我为结构数组分配内存的方式，以及for循环中每个结构的.name字段的问题。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <conio.h>
#define MAX_NAME_LEN 50
typedef struct stud
{
char *name;
int marks[4];
float avg;
}student;
student* Create_Class(int);
void Avg_Mark(student*);
void Print_One(student*);
void printExcellent(student*);
void main()
{
int size, i;
student *arr, *newArr;
printf("\nEnter the number of students: ");
scanf_s("%d", &size);
newArr = Create_Class(&size);
for (i = 0; i < size; i++)
{
printExcellent(newArr+i);
}
for (i=0;i<size;i++) free(newArr[i].name);
free(newArr);
_getch();
}
student* Create_Class(int size)
{
student *p;
char str[MAX_NAME_LEN];
int i, j;
p = (student*)calloc(size , sizeof(student));
if (!p)
{
printf("Memory allocation failure.");
exit(1);
}
for (i = 0; i < size; i++)
{
printf("Enter your name: ");
rewind(stdin);
gets(str);
p[i].name = (char*)calloc(strlen(str)+1,sizeof(char));
if (!(p[i].name))
{
printf("Memory allocation error!");
exit(1);
}
strcpy_s(p[i].name,50,str);
printf("Enter your marks: ");
for (j = 0; j < 4; j++)
{
scanf_s("%d", &p[i].marks[j]);
}
Avg_Mark(p + i);
}
return p;
}
void Avg_Mark(student* s)
{
int i, sum=0;
for (i = 0; i < 4; i++)
sum += s->marks[i];
s->avg = (float)sum / 4;
}
void Print_One(student* s)
{
printf("The average of %s is %.1f\n", s->name, s->avg);
}
void printExcellent(student* s)
{
if ((s->avg) > 85)
Print_One(s);
}
要指出我看到的所有可疑的东西：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <conio.h>
#define MAX_NAME_LEN 50
typedef struct stud
{
char *name;
int marks[4];
float avg;
}student;
student* Create_Class(int);
void Avg_Mark(student*);
void Print_One(student*);
void printExcellent(student*);
void main()
{
int size, i;
student *arr, *newArr;
printf("\nEnter the number of students: ");
scanf_s("%d", &size);
// This is wrong. Remove the &...
newArr = Create_Class(&size);
for (i = 0; i < size; i++)
{
printExcellent(newArr+i);
}
for (i=0;i<size;i++) free(newArr[i].name);
free(newArr);
_getch();
}
student* Create_Class(int size)
{
student *p;
char str[MAX_NAME_LEN];
int i, j;
// Consider checking size for a sane value.
// Ok, allocate an array of students.
p = (student*)calloc(size , sizeof(student));
if (!p)
{
printf("Memory allocation failure.");
exit(1);
}
for (i = 0; i < size; i++)
{
printf("Enter your name: ");
// These 2 lines scare the heck out of me. I'd really do this differently.
// gets is the devil and the see:
// https://stackoverflow.com/questions/20052657/reversing-stdin-in-c
// for why this may not work well.
rewind(stdin);
gets(str);
// What if str is not a terminated string? Then 1 char of 0? Guess this is ok. Hope it doesn't overflow on the copy below though (consider fixed max size and not using a temporary)
p[i].name = (char*)calloc(strlen(str)+1,sizeof(char));
if (!(p[i].name))
{
printf("Memory allocation error!");
exit(1);
}
// Do a fast copy of up to 50 chars. I'd really want to verify this output to be sure it works.
strcpy_s(p[i].name,50,str);
printf("Enter your marks: ");
for (j = 0; j < 4; j++)
{
// Hope this inputs the way you want.
scanf_s("%d", &p[i].marks[j]);
}
// This should work, but I prefer more explicit pointers.
Avg_Mark(p + i);
}
return p;
}
void Avg_Mark(student* s)
{
// What if s is Null?
int i, sum=0;
// 4 is a magic number. Make this a constant.
for (i = 0; i < 4; i++)
sum += s->marks[i];
// This won't be as accurate as you want. Consider an integer solution.
s->avg = (float)sum / 4;
}
void Print_One(student* s)
{
// What if s is Null? What about s->name?
printf("The average of %s is %.1f\n", s->name, s->avg);
}
void printExcellent(student* s)
{
// What if s is Null?
if ((s->avg) > 85)
Print_One(s);
}
注意：在浏览此代码时，我没有看到任何“红色标志”，除了大小和可能的获取/回放调用。我仍然会在函数中添加null断言，并使用调试器来完成它，以确保一切都符合您的预期。老实说，这里有足够的内容，我更喜欢调试器帮助，以便在编写注释时快速查看代码。
更新
如果我将你所有的scanf_s更改为scanf()调用，将你的gets() / rewind()调用替换为简单的scanf("%s", str)调用，并将你的时髦的strcpy_s()函数更改为更简单的strcpy()或strncpy()调用，你的程序似乎不会让我崩溃。我的钱是strcpy_s()调用正在破坏RAM，同时做“快速”复制。