Question

How to delete the middle element of a stack in C++

Answer 1

#include <iostream>
#include <stack> 

void deleteMiddleElement(std::stack<char> &st, int size, int current = 0) { 
    if (st.empty() || current == size) { 
        return; 
    }
    
    char el = st.top(); 
    st.pop();
    
    deleteMiddleElement(st, size, current + 1); 
    
    if (current != size / 2) { 
        st.push(el); 
    }
}

int main() { 
    std::stack<char> st; 
    
    st.push('3'); 
    st.push('5'); 
    st.push('1'); 
    st.push('m'); 
    st.push('9'); 
    st.push('2'); 
    st.push('7'); 
    
    deleteMiddleElement(st, st.size()); 
    
    while (!st.empty()) { 
        char el = st.top(); 
        st.pop(); 
        std::cout << el << " "; 
    } 
}




/*
run:

7 2 9 1 5 3 

*/

 

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