private:

int size = 10, length = 0;

int* arr = new int[10];

void SizeDoubler(){

int *temp, *temp1;

temp = new int[size*2];

for(int i = 0; i < size; i++) temp[i] = arr[i];

temp1 = arr;

arr = temp;

free(temp1);

temp = NULL;

size *= 2;

}

//append

public:

void append(int num){

if(length >= size) SizeDoubler();

arr[length++] = num;

}

//insert

void insert(int psn, int val){

while(psn > size-1) SizeDoubler();

if(length+1 == size) SizeDoubler();

for(int i = length-1; i >= psn; i--) arr[i+1] = arr[i];

arr[psn] = val;

length++;

}

//display

void print(){

for(int i = 0; i < length; i++) cout << arr[i] << " ";

cout << endl;

}

// delete

void del(int psn){

for(int i = psn; i < length-1; i++) arr[i] = arr[i+1];

length--;

}

// search

//linear search

void search(int val){

int i;

for(i = 0; i < length; i++) if(arr[i] == val){ cout << val << " found at " << i << endl; break; }

if (i == length) cout << val << " not found" << endl;

}

// get

int get(int psn){ return arr[psn];}

//set

void set(int psn, int val){

while(psn > size) SizeDoubler();

arr[psn] = val;

if(length <= psn) length = psn+1;

}

// max

int max(){

int ans = INT_MIN;

for(int i = 0; i < length; i++) if(arr[i] > ans) ans = arr[i];

return ans;

}

// min

int min(){

int ans = INT_MAX;

for(int i = 0; i < length; i++) if(arr[i] < ans) ans = arr[i];

return ans;

}

// reverse

void reverse(){

for(int i = 0; i <= length/2; i++){

int temp = arr[i];

arr[i] = arr[length-1-i];

arr[length-i-1] = temp;

}

}

//size of array

int len(){return length;}

//findMissingin sorted

int findMissing1();

//findMissingin unsorted

int findMissing2(int a, int b);

//pair of sum with k

void sumK(int k);