Merge pull request matthewsamuel95#816 from Riei-Joaquim/patch-1

Create stack_using_linked_list.cpp

Author: matthewsamuel95

Data Structures/Stack/stack_using_linked_list.cpp

@@ -0,0 +1,92 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define stack_empty -1
+class pilha{
+    private:
+        struct node{
+            int dado;
+            node *prox;
+        };
+        node *head = nullptr;
+
+    public:
+        void push(int val){
+            node* elemento;
+            elemento = new node;
+            elemento->dado = val;
+            if(head == nullptr){
+                //pilha vazia
+                elemento->prox = nullptr;
+                head = elemento;
+            }else{
+                //pilha com elemento
+                elemento->prox = head;
+                head = elemento;
+            }
+        }
+
+        bool isempty(){
+            if(head == nullptr){
+                return true;
+            }
+            return false;
+        }
+
+        int pop(){
+            int val = stack_empty;
+            if(!isempty()){
+                val = head->dado;
+                node *next, *at;
+                next = head->prox;
+                at = head;
+                head = next;
+                delete at;
+            }
+            return val;
+        }
+
+        int show_top(){
+            int val = stack_empty;
+            if(!isempty()){
+                val = head->dado;
+            }
+            return val;
+        }
+
+        int size(){
+            int cont = 0;
+            node* aux;
+            aux = head;
+            while(aux->prox !=nullptr){
+                cont++;
+                aux = aux->prox;
+            }
+            cont++;
+            return cont;
+        }
+};
+
+int main(){
+    pilha st;
+    int val;
+
+    for(int i = 0; i < 10; i++){
+        st.push((i+1));
+    }
+    for(int i = 0; i <12; i++){
+        val = st.pop();
+        if(val != stack_empty){
+            cout << val << endl;
+        }else{
+            cout << "stack is empty!" << endl;
+        }
+    }
+
+    for(int i = 0; i < 5; i++){
+        st.push((i+1));
+    }
+
+    cout << "stack have " << st.size() << " elements" << endl;
+    cout << st.show_top() << " is top element of stack" << endl;
+    return 0;
+}