Add files via upload

Author: RezaGooner

Postfix/Postfix.cpp

@@ -0,0 +1,107 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+const int MAX_SIZE = 100;
+
+struct Stack {
+    int top; // index of top of stack
+    string elements[MAX_SIZE];
+};
+
+bool isEmpty(Stack& stack) {
+    return stack.top == -1;
+}
+
+bool isFull(Stack& stack) {
+    return stack.top == MAX_SIZE - 1;
+}
+
+void push(Stack& stack, string value) {
+    if (isFull(stack)) {
+        cout << "Stack overflow!" << endl;
+        return;
+    }
+    stack.elements[++stack.top] = value;
+}
+
+void pop(Stack& stack) {
+    if (isEmpty(stack)) {
+        cout << "Stack underflow!" << endl;
+        return;
+    }
+    stack.elements[stack.top--] = "";
+}
+
+string top(Stack& stack) {
+    if (isEmpty(stack)) {
+        return "";
+    }
+    return stack.elements[stack.top];
+}
+
+string removeSpaces(string str) {
+    string result;
+    for (int i = 0 ; i < str.size() ; i++) {
+        if (str[i] != ' ') {
+            result += str[i];
+        }
+    }
+    return result;
+}
+
+void postfix(Stack& stack, string phrase) {
+    for (int i = 0; i < phrase.size(); i++) {
+        string p = string(1, phrase[i]);
+        if (p >= "0" && p <= "9") {
+            cout << p;
+        } else if (p == "(" || p == ")" || p == "{" || p == "}" || p == "[" || p == "]") {
+            push(stack, p);
+        } else {
+            while (true) {
+                if (isEmpty(stack) || top(stack) == "(" || top(stack) == "[" || top(stack) == "{") {
+                    push(stack, p);
+                    break;
+                } else if (top(stack) == "+" || top(stack) == "-" || top(stack) == "/" ||
+                           top(stack) == "*") {
+                    if ((p == "*" || p == "/") && (top(stack) == "-" || top(stack) == "+")) {
+                        push(stack, p);
+                        break;
+                    } else {
+                        if (top(stack) != "(" && top(stack) != ")" && top(stack) != "{" &&
+                            top(stack) != "}" && top(stack) != "[" && top(stack) != "]") {
+                            cout << top(stack);
+                        }
+                        pop(stack);
+                    }
+                } else {
+                    break;
+                }
+            }
+        }
+    }
+    while (!isEmpty(stack)) {
+        string p = top(stack);
+        if (p != "(" && p != ")" && p != "{" && p != "}" && p != "[" && p != "]") {
+            cout << p;
+        }
+        pop(stack);
+    }
+}
+
+int main() {
+    Stack stack;
+    stack.top = -1;
+    string str;
+    cout << "Enter the phrase: ";
+    getline(cin,str);
+    postfix(stack, removeSpaces(str));
+
+    return 0;
+}
+
+/*
+    Reza Asadi (Github : RezaGooner)
+	1402/08/22 ~ 2023/11/13
+*/