A C experiment, I don t know what the problem is, let s help

while(j<=i) is an endless loop.

int j=0 should be j=1

insert(sqlist,q,3,9) should be insert(sqlist,sqlist,3,9).

Because for(; p!=null;p=p->next)

printf("%d ",p->data);

After doing the math, p=null

The correction is as follows:

#include

#include

struct sq

int data;

struct sq *next;

struct sq * insert(struct sq *head,struct sq *p,int i,int e)

struct sq *p1,*p2;

int j=1;

p2=(struct sq*)malloc(sizeof(struct sq));

p2->data=e;

p1=head;

while(j++<=i)

p=p->next;

p2->next=p->next;p->next=p2;

return(head);

int main()

struct sq * insert(struct sq *head,struct sq *p,int i,int e);

struct sq a,b,c,d,*sqlist,*p;

sqlist=&a;

;;p=sqlist;

printf("The raw data is: ");

for(;p!=null;p=p->next)

printf("%d ",p->data);

printf("");

printf("Insert a linked list after 4 between 5 and 9. n");

insert(sqlist,sqlist,3,9);

for(p=sqlist;p->next!=null;p=p->next)

printf("%d",p->data);

return 0;

insert function definition.

while loop.

while(jnext;

j++;Notice the boundaries of the lower loop. There is also a problem with the last output function, which does not output the last node.

If you look closely, it seems that there are a lot of mistakes!

3, ba = a + 7;Because it has a semicolon, it is a statement, not an expression.

a=7+b+c, a++ is a comma expression.

4,cint a[2][3]=,,} is one dimension less, a[3][3] is right.

6，bint a=b=0;b is not defined and cannot be used to define a12, c

This is how function pointers are defined.

13,A This is simple and should not go wrong.

15,afopen The first argument is const char*

My answer is aabcaaddbcddadc, mine may also be wrong, FYI.

The third question is wrong, the title says "expressions that conform to the grammar of the C language", and A is a statement, not an expression.

It should be the fourth question of B, you should choose C, it is estimated that you chose the wrong question sloppily, do not explain the sixth question, you should choose B, C can not be declared like this, unless you have previously stated B Question 12, you should choose C, there is no reason.

Question 13, there is nothing to explain,!A is equivalent to A==0 Question 15, and A should be chosen

2. a

3.b should be a is a statement, it has; Therefore it is not an expression, if it is not; Then A satisfies the topic.

4 .c A curly brace is a line, and it has 3 curly braces, that is, it assigns a value of 3 lines greater than the specified number of lines 2, so D is wrong.

6. b13. a

15.aThe other answers are correct.

Your question 4 is wrong, it should be c; Question 13 should be A

1. Error reason, variable name cannot be a number.

2. d=, c=

3. a=4,b=4,c=2,d=2,i=3,j=4,m=3,n=24. a=-32

Item B is incorrect.

int a=1;

dowhile(a<=10)

The while() of do-while should be followed by a semicolon and a ......Most statements end with a semicolon and include the definition of the class.

b Not true.

dowhile(..

The last semicolon is missing.

b is not right, there is no semicolon at the end.

b is incorrect, and a semicolon is missing from the last line";"