ADT：Set

Array

size()

int i=0;
while((i<limit)&&(s[i]!=null)){
    i++;
}
return i;

add()

int i=0;
while((i<limit)&&(s[i]!=null)&&(s[i]!=x)
    i++;
if(i==limit)
    Problem: Arrary Full;
else if (s[i]==x)
    Problem: x already there;
else 
    s[i]=x;

delete()

int i=0;
while((i<limit)&&s[i]!=x)&&(s[i]!=null)
    i++;
if(i==limit)||(s[i]==null)
    Problem: No such element;
else{
    i++;
    while((i<limit)&&(s[i]!=null)){
    s[i-1]=s[i];
    i++;
    }
    s[i-1]=null;
}

---

Linked List

size() add() delete() 时间复杂度均为 O(n)

exists(x)

p=top;
while(p!=NULL){
    if(p->value==x){
        return true;
    }
    p=p->next;
}
return false;

add(x)

void add(x) {  
	if (!exists(x)) {  
	    node *p = new node();  
	    p->value=x;
        p->next=top; 
	    top=p;  
	}
}