a test for the c programming language

　　i. history

　　1. c was originally designed for and implemented on the (what) operating system on the dec pdp-11, by (who) .

　　2. the most recently approved ansi/iso c standard was issued in (when) , and single line comments notation “//” is or isn’t a feature of c89.

　　ii. syntax and semantics

　　1. in a runtime c program, auto variables are stored in , static variables are stored in , and function parameters are stored in .

　　a. stack b. heap c. neither stack nor heap

　　2. the statement “extern int x;” is a , and the keyword extern is used during .

　　a. variable declaration b. variable definition

　　c. compilation time d. runtime

　　3. there is a complicated declaration: void ( * signal (int, void (*)(int)) ) (int);

　　if a statement “typedef void (*p) (int);” is given, please rewrite this complicated declaration.

　　4. the following code is a segment of c program.

　　..........

　　void func(int *p)

　　{...........}

　　..........

　　main()

　　{

　　int num=0;

　　.........

　　func(&num);

　　........

　　}

　　..........

　　here, the function argument “&num” is passed .

　　a. by value b. by reference

　　iii. practice

　　create a tree, which has h (h>0) layers, and its each node has w (w>0) sub-nodes.

　　please complete the following incomplete solution.

　　#include

　　#include

　　struct tree{

　　char info;

　　p_sub; //link to sub-nodes

　　};

　　// allocate memory and initiate

　　void dnode ( struct tree* tmp )

　　{

　　=malloc( sizeof (struct tree) );

　　= 0x41;

　　= null;

　　}

　　struct tree *dtree (struct tree* subtree, int height, int width)

　　{

　　int i;

　　if ( !subtree ) //if necessary, allocte memory for subtree

　　denode(subtree);

　　if ( height == 1 )

　　return subtree;

　　else if ( height == 2 ) {

　　struct tree *leaf = null;

　　for ( i=0; i

　　denode ( );

　　;

　　leaf = null;

　　}

　　return subtree;

　　}

　　else {

　　for ( i=0; i

　　}

　　return subtree;

　　}

　　}

　　main()

　　{

　　.........

　　struct tree *root = null;

　　root = dtree (root, h, w) ; // h and w are integers get from input

　　.........

　　}