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2008-11-03T05:19:34Z

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Lab 4

I started coding the length method by writing a for loop similiar to the one in the print_list method. The difference is that there needed to be a counter to keep track of all the elements.
<pre>
int length(Cons* list) {
int i;
if (list->tail == 0)
return 0;
else {
for (i = 0; list != nil; list = list->tail ) {
i++;
}
return i;
}
}
</pre>

When writing code to check the first element in the cons cell, I first made a condition that if the 'list->==nil' then 0 would be returned. Else 'list->head' would be returned.

<pre>
element_t first(Cons* list) {
if (list->tail == nil)
return 0;
else
return list->head;
}
</pre>

Doing the second element was harder because it required a loop, I used the same loop and conditions for the third and fourth element but with the condition incremented slightly for each method.

<pre>
element_t second(Cons* list) {
int i;
if (list->tail == nil)
return 0;
for (i = 0; i<1; list = list->tail ) {
i++;
}
if (!(list->head==0))
return list->head;
else
return 0;
}
</pre>

The code for the nth element was straightforward because a template of element at second can be used with the for loop using the variable that indicats which element wants to be viewed.

<pre>
element_t nth(int n,Cons* list) {
int i;
if (list->tail == nil && n>0 )
return 0;
else {
for (i = 0; i<(n-1); list = list->tail ) {
i++;
}
}
if (!(list->head==0))
return list->head;
else
return 0;
}
</pre>

SE250:lab-4:hals016 - Revision history

Mark: 4 revision(s)