Simulate the specified operations using a set data structure.
Algorithm implementation
Declare a set .
set<int> s;Read the input data.
while (cin >> op >> x)
{Insert an element into the set.
if (op == "insert") s.insert(x); elseRemove an element from the set if it exists there.
if (op == "delete") s.erase(x); else
{Check if an element exists in the set.
if (s.find(x) != s.end()) printf("true\n");
else printf("false\n");
}
}Java implementation
import java.util.*;
public class Main
{
public static void main(String []args)
{
Scanner con = new Scanner(System.in);
TreeSet<Integer> s = new TreeSet<Integer>();
while(con.hasNext())
{
String c = con.next();
int x = con.nextInt();
if (c.charAt(0) == 'i') s.add(x); else
if (c.charAt(0) == 'd') s.remove(x); else
{
if (s.contains(x))
System.out.println("true");
else
System.out.println("false");
}
}
con.close();
}
} Python implementation
import sysDeclare a set.
s = set()Read the input data.
for line in sys.stdin:
op, x = line.split()
x = int(x)Insert an element into the set.
if op == "insert":
s.add(x)Remove an element from the set if it exists there.
elif op == "delete":
s.discard(x)
else:Check if an element exists in the set.
if x in s:
print("true")
else:
print("false")