Hey! I've done this in c. Some of the test cases are accepted but the others show segmentation fault. Any suggestions?

#include<stdio.h>
int main()
{
	int i,n,k,num;
	scanf("%d %d",&n,&k);
	int arr[k];
	arr[0]=2;
	arr[1]=(2*n)+1;
	num=arr[0]+arr[1];
	for(i=2;i<k;num++)
	{
		if(sumcheck(num,arr,i))
		{
			arr[i]=num;
			i++;
		}
	}
	printf("%d",arr[k-1]);
	return 0;
}
int sumcheck(int num,int arr[],int size)
{
	int i,j,k=0;
	for(i=0;i<size;i++)
	{
		for(j=0;j<size;j++)
		{
			if(arr[j]+arr[i]==num)
			{
				k++;
			}
		}
	}
	if(k==2)
	{
		return 1;
	}
	else
	{
		return 0;
	}
}

public class Solution {

public static void main(String[] args) {
Scanner in = new Scanner(System.in); 
 try{

 int n = in.nextInt(); 
 int k = in.nextInt(); 

 int array[] = new int[k+1]; 

    array[0]=2; 
   array[1]=2*n+1; 
    List<Integer> list2 = new ArrayList<Integer>();
   for(int i = 2; i<k; i++){
        List<Integer> list = new ArrayList<Integer>();

       for(int j = 0; j<i-1; j++){
           for(int kk=j+1; kk<i; kk++){
               int a = array[j]+array[kk]; 
               if(a>array[i-1]){list.add(a);}; 
           }
       }
      Collections.sort(list);
            // System.out.println("list 1"+ list );
      Set<Integer> set = new HashSet<Integer>(list);

  for(Integer tmp:set)
     {       
      if(Collections.frequency(list, tmp)==1){
                list2.add(tmp);       
      }
}

     Collections.sort(list2); 
       array[i]=list2.get(0); 
      //System.out.println("list 1" +list2 );
       list2.clear(); 
   }
  System.out.println(array[k-1] );



}catch(Exception e){
    System.out.println("Error"); 
}
}      

}

def check(li,c):
    ii=0
    flag=1
    smallestval=c
    for i in li:
        for j in li[ii:]:
            if i==j:
                pass
            else:
                val=int(i)+int(j)

                if smallestval!=val and val>c:
                  if (val<smallestval and smallestval!=c):
                        smallestval=val
                if smallestval==c:
                    if val>smallestval:
                          smallestval=val

        ii+=1
    f=0
    ii=0
    for i in li:
        for j in li[ii:]:
            if int(i)+int(j)==smallestval:
                f+=1

        ii+=1

    if f==1:
        return smallestval
    return c
k = 1
v1, k = raw_input("enter two numbers").split()
if int(v1)>=2 and int(v1)<=10:
    if int(k)>=1 and int(k)<=10**11:
        v2 = 2 * int(v1) + 1
        li = []
        li.append(v1)
        li.append(v2)
        li.append(int(v1) + int(v2))
        c=int(v1)+int(v2)
        while len(li) != int(k):

            copy=c
            c = check(li,c)
            if copy==c:
                c+=1
                continue
            li.append(c)
        print li[int(k)-1]

it takes a bit long time, can anyone please let me know a better way to do it.. it worked for the first test case though.

import java.util.; import java.text.; import java.math.; import java.util.regex.;

public class Solution {

public static void main(String[] args) {
Scanner in = new Scanner(System.in); 
 int n = in.nextInt(); 
 int k = in.nextInt(); 

 int array[] = new int[k+2]; 
   array[0]=n; 
   array[1]=2*n+1; 

    if(k>2){
List<Integer> list2 = new ArrayList<Integer>();
   for(int i = 2; i<=k; i++){
        List<Integer> list = new ArrayList<Integer>();

       for(int j = 0; j<i-1; j++){
           for(int kk=j+1; kk<i; kk++){
               int a = array[j]+array[kk]; 
               if(a>array[i-1]){list.add(a);}; 
           }
       }
      Collections.sort(list);
      Set<Integer> set = new HashSet<Integer>(list);

  for(Integer tmp:set)
     {       
      if(Collections.frequency(list, tmp)==1){
                list2.add(tmp);       
      }
}

     Collections.sort(list2); 
       array[i]=list2.get(0); 

       list2.clear(); 
   }
    }
  System.out.println(array[k-1] );

}} 

Can anyone please suggest a optimal logic. Mine is giving a TLE. Thanks in advance.'