Answers for "stack in stl"

stack stl

#include <iostream>
#include<stack>
#include<algorithm>

using namespace std;

int main()
{
    stack<int>st;
    stack<int>st1;
    st.push(100);
    st.push(90);
    st.push(80);
    st.push(70);
    st.pop();
    st1.push(10);
    st1.push(20);
    st1.push(30);
    while(!st.empty())
    {
        cout<<st.top()<<" ";
        st.pop();
    }
    cout<<endl;
    while(!st1.empty())
    {
        cout<<st1.top()<<" ";
        st1.pop();
    }
    cout<<endl;
    st.push(100);
    st.push(90);
    st.push(80);
    st.push(70);
    st.pop();
    st1.push(10);
    st1.push(20);
    st1.push(30);
    st.swap(st1);
     while(!st.empty())
    {
        cout<<st.top()<<" ";
        st.pop();
    }
    cout<<endl;
     while(!st1.empty())
    {
        cout<<st1.top()<<" ";
        st1.pop();
    }
    cout<<endl;
    return 0;
}

stack c++

stack<int> stk;
stk.push(5);
int ans = stk.top(5); // ans =5
stk.pop();//removes 5

cpp stack

// Fast DIY Stack
template<class S, const int N> class Stack {
private:
    S arr[N];
    int top_i;

public:
    Stack() : arr(), top_i(-1) {}
    void push (S n) {
        arr[++top_i] = n;
    }
    void pop() {
        top_i--;
    }
    S top() {
        return arr[top_i];
    }
    S bottom() {
        return arr[0];
    }
    int size() {
        return top_i+1;
    }
};