From 768000285e16977d62d2ab01f80722b49c848cee Mon Sep 17 00:00:00 2001
From: Marat Izmailov <marat.izmailov@student.tuke.sk>
Date: Thu, 17 Oct 2024 12:19:39 +0000
Subject: [PATCH] Update cv3/program.c

---
 cv3/program.c | 153 +++++++++++++++++++-------------------------------
 1 file changed, 59 insertions(+), 94 deletions(-)

diff --git a/cv3/program.c b/cv3/program.c
index d68d985..d21f9cb 100644
--- a/cv3/program.c
+++ b/cv3/program.c
@@ -1,116 +1,81 @@
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
-#include <assert.h>
-#include <ctype.h>
 
 #define STACK_SIZE 10
 
+double stack[STACK_SIZE];
+int top = 0;
 
-struct stack {
-    float values[STACK_SIZE];
-    int size;
-};
-
-
-void init_stack(struct stack* s) {
-    memset(s, 0, sizeof(struct stack));
-}
-
-
-void push_stack(struct stack* s, float value) {
-    assert(s->size < STACK_SIZE); 
-    s->values[s->size] = value;
-    s->size += 1;
-}
-
-
-float pop_stack(struct stack* s) {
-    assert(s->size > 0); 
-    s->size -= 1;
-    return s->values[s->size];
-}
-
-
-void print_stack(struct stack* s) {
-    for (int i = 0; i < s->size; i++) {
-        printf("%.2f ", s->values[i]);
+void print_stack() {
+    for (int i = 0; i < top; i++) {
+        printf("%.2f ", stack[i]);
     }
     printf("\n");
 }
 
-
-int is_number(const char* str) {
-    char* endptr;
-    strtof(str, &endptr);
-    return endptr != str && *endptr == '\0'; 
+int push(double value) {
+    if (top >= STACK_SIZE) {
+        printf("full stack\n");
+        return 0;
+    }
+    stack[top++] = value;
+    print_stack();
+    return 1;
 }
 
+int pop(double *value) {
+    if (top <= 0) {
+        printf("not enough operands\n");
+        return 0;
+    }
+    *value = stack[--top];
+    return 1;
+}
+
+int apply_operation(char op) {
+    double a, b;
+
+    if (!pop(&b) || !pop(&a)) {
+        return 0;
+    }
+
+    double result;
+    switch (op) {
+        case '+': result = a + b; break;
+        case '-': result = a - b; break;
+        case '*': result = a * b; break;
+        case '/':
+            if (b == 0) {
+                printf("division by zero\n");
+                return 0;
+            }
+            result = a / b;
+            break;
+        default:
+            printf("bad input\n");
+            return 0;
+    }
+
+    return push(result);
+}
 
 int main() {
-    struct stack mystack;
-    init_stack(&mystack);
+    char input[100];
 
-    char input[20]; 
+    while (scanf("%s", input) == 1) {
+        char *end;
+        double value = strtod(input, &end);
 
-    while (1) {
-        printf("Enter a number or an operation (+, -, *, /): ");
-        if (!fgets(input, sizeof(input), stdin)) {
-            break; 
-        }
-
-        
-        input[strcspn(input, "\n")] = 0;
-
-        if (is_number(input)) {
-            
-            float value = strtof(input, NULL);
-            push_stack(&mystack, value);
-            print_stack(&mystack);
+        if (*end == '\0') {
+            if (!push(value)) return 0;
+        } else if (input[1] == '\0' && strchr("+-*/", input[0])) {
+            if (!apply_operation(input[0])) return 0;
         } else {
-            
-            if (mystack.size < 2) {
-                printf("Error: Not enough values on the stack to perform operation.\n");
-                break; 
-            }
-            float b = pop_stack(&mystack);
-            float a = pop_stack(&mystack);
-            float result = 0; 
-
-            switch (input[0]) {
-                case '+':
-                    result = a + b;
-                    break;
-                case '-':
-                    result = a - b;
-                    break;
-                case '*':
-                    result = a * b;
-                    break;
-                case '/':
-                    if (b == 0) {
-                        printf("Error: Division by zero.\n");
-                        
-                        push_stack(&mystack, a);
-                        push_stack(&mystack, b);
-                        print_stack(&mystack);
-                        continue; 
-                    }
-                    result = a / b;
-                    break;
-                default:
-                    printf("Error: Unknown operation '%s'.\n", input);
-                    
-                    push_stack(&mystack, a);
-                    push_stack(&mystack, b);
-                    print_stack(&mystack);
-                    continue; 
-            }
-
-            push_stack(&mystack, result);
-            print_stack(&mystack);
+            printf("bad input\n");
+            return 0;
         }
     }
 
+    printf("no input\n");
     return 0;
 }