#include <bits/stdc++.h>
using namespace std;

// pop from one of three stacks placed in a single array
int pop(int stno, vector<int> &arr, int &t1, int &t2, int &t3) {
  // handle stack 0
  if (stno == 0) {
    // check non-empty condition as in given code
    if (t1 != 0) {
      // return element and decrement top
      return arr[t1--];
    }
  }
  // handle stack 1
  else if (stno == 1) {
    // check non-empty condition as in given code
    if (t2 != 0) {
      // return element and decrement top
      return arr[t2--];
    }
  }
  // handle stack 2
  if (t3 != 0) {
    // return element and decrement top (as in given code)
    return arr[t1--];
  }
  // return INT_MAX when underflow by convention in the code
  return INT_MAX;
}

// push into one of three stacks placed in a single array
void push(int ele, int stno, int &t1, int &t2, int &t3,
          int &b1, int &b2, int &b3, vector<int> &arr) {
  // notify push
  cout << "Element pushed in the stack" << endl;
  // push to stack 0
  if (stno == 0) {
    // check overflow for segment 0
    if (t1 == b1) {
      // print overflow
      cout << "overflow";
      // return early
      return;
    }
    // place element after incrementing top
    else arr[++t1] = ele;
  }
  // push to stack 1
  else if (stno == 1) {
    // check overflow for segment 1
    if (t2 == b2) {
      // print overflow
      cout << "overflow";
      // return early
      return;
    }
    // place element after incrementing top
    else arr[++t2] = ele;
  }
  // push to stack 2
  else {
    // check overflow for segment 2
    if (t3 == b3) {
      // print overflow
      cout << "overflow";
      // return early
      return;
    }
    // place element after incrementing top
    else arr[++t3] = ele;
  }
  // finish
  return;
}

// program entry
int main() {
  // set total array size
  int n = 9;
  // number of stacks (unused, kept for parity)
  int k = 3;
  // allocate backing array
  vector<int> arr(n);
  // initialize tops for three stacks
  int t1 = -1, t2 = 2, t3 = 5;
  // define segment boundaries for three stacks
  int b1 = t1 + 3, b2 = t2 + 3, b3 = t3 + 3;
  // push element 11 into stack 0
  push(11, 0, t1, t2, t3, b1, b2, b3, arr);
  // push element 13 into stack 0
  push(13, 0, t1, t2, t3, b1, b2, b3, arr);
  // print pop result text
  cout << "Element popoed from the stack " << pop(0, arr, t1, t2, t3);
  // exit
  return 0;
}
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