write a program in C++ to implement 2 stacks in one array where 1st stack will start from 0th index &2nd from last index
Answers
#include <iostream>
#include <stdlib.h>
using namespace std;
class twoStacks {
int* arr;
int size;
int top1, top2;
public:
// Constructor
twoStacks(int n)
{
size = n;
arr = new int[n];
top1 = n / 2 + 1;
top2 = n / 2;
}
// Method to push an element x to stack1
void push1(int x)
{
// There is at least one empty
// space for new element
if (top1 > 0) {
top1--;
arr[top1] = x;
}
else {
cout << "Stack Overflow"
<< " By element :" << x << endl;
return;
}
}
// Method to push an element
// x to stack2
void push2(int x)
{
// There is at least one empty
// space for new element
if (top2 < size - 1) {
top2++;
arr[top2] = x;
}
else {
cout << "Stack Overflow"
<< " By element :" << x << endl;
return;
}
}
// Method to pop an element from first stack
int pop1()
{
if (top1 <= size / 2) {
int x = arr[top1];
top1++;
return x;
}
else {
cout << "Stack UnderFlow";
exit(1);
}
}
// Method to pop an element
// from second stack
int pop2()
{
if (top2 >= size / 2 + 1) {
int x = arr[top2];
top2--;
return x;
}
else {
cout << "Stack UnderFlow";
exit(1);
}
}
};
/* Driver program to test twStacks class */
int main()
{
twoStacks ts(5);
ts.push1(5);
ts.push2(10);
ts.push2(15);
ts.push1(11);
ts.push2(7);
cout << "Popped element from stack1 is "
<< " : " << ts.pop1()
<< endl;
ts.push2(40);
cout << "\nPopped element from stack2 is "
<< ": " << ts.pop2()
<< endl;
return 0;
}
Output :
Stack Overflow By element :7
Popped element from stack1 is : 11
Stack Overflow By element :40
Popped element from stack2 is : 15