From 0ac9d77192124ba298edace6f889237da2d5b7e6 Mon Sep 17 00:00:00 2001
From: Daniel Ryzhuk <daniel.ryzhuk@student.tuke.sk>
Date: Wed, 14 Oct 2020 16:46:27 +0000
Subject: [PATCH] Upload files to 'cv3'

---
 cv3/program.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 cv3/program.c

diff --git a/cv3/program.c b/cv3/program.c
new file mode 100644
index 0000000..38ade7b
--- /dev/null
+++ b/cv3/program.c
@@ -0,0 +1,84 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#define STACK_SIZE 10
+
+typedef struct {
+    float values[STACK_SIZE];
+    int size;
+} stack;
+
+void stack_print (stack* stack);
+void stack_push (stack* stack,float value);
+float stack_pop (stack* stack);
+void my_exit(int flag, const char* input);
+
+int main(void) {
+    stack* p_stack = (stack*) malloc(sizeof(stack));
+    memset(p_stack, 0, sizeof(stack));
+    while(1) {
+        char str[128] = { 0 };
+        char* tres = fgets(str, 128, stdin);
+        if(tres == NULL || str[0] == 0 || (str[1] == 0 && str[0] == '\n'))
+            my_exit(1, "no_input");
+        str[strlen(str) - 1] = 0;
+        // if number
+        if(strlen(str) > 1 || (str[0] >= '0' && str[0] <= '9')) {
+            char *p;
+            errno = 0;
+            float res = strtod(str,&p);
+            my_exit(str[0] == '.' || errno || (*p) != 0, "bad input");
+            stack_push(p_stack, res);
+        }
+        else {
+            my_exit(p_stack->size < 2, "not enough operands");
+            float b = stack_pop(p_stack);
+            float a = stack_pop(p_stack);
+            char op = str[0];
+            float res;
+            switch (op) {
+                case '+':
+                    res = a + b;
+                    break;
+                case '-':
+                    res = a - b;
+                    break;
+                case '*':
+                    res = a * b;
+                    break;
+                case '/':
+                    my_exit(b == 0.f, "division by zero");
+                    res = a / b;
+                    break;
+                default:
+                    my_exit(1, "bad input");
+            }
+            stack_push(p_stack, res);
+        }
+        stack_print(p_stack);
+    }
+    free(p_stack);
+}
+
+void stack_print(stack* st) {
+    for(int i = 0; i < st->size; i++)
+        printf("%.2f ",st->values[i]);
+    printf("\n");
+}
+
+void stack_push(stack* st, float push_value) {
+    if(st->size < STACK_SIZE)
+        st->values[st->size++] = push_value;
+}
+
+float stack_pop(stack* st) {
+    if(st->size > 0)
+        return st->values[--st->size];
+}
+
+void my_exit(int flag, const char* input) {
+    if (flag) {
+        printf("%s\n", input);
+        exit(0);
+    }
+}
\ No newline at end of file