DataStructures/stackpostfix.c at main · suhedacilek/DataStructures · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
#include<stdio.h>

int stack[20];
int top = -1;

void push(int x){

	stack[++top] = x;
}

int pop(){

	return stack[top--];
}

int main(){
	char exp[20];
    char *e;
    int n1,n2,n3,num;

    printf("Enter the expression : ");
    scanf("%s",exp);
    e = exp;

    while(*e != '\0')
    {
    	if(isdigit(*e)){ // isdigit karakterin sayisal olup olmadigini kontrol eder.

			num = *e -48; // 0'ýn ASCII tablosundaki karsiligini veriyor. 6 ascii de 54 degerine sahip 54-48 = 6 yý verir.
            push(num);
        }
    	else{
        	n1 = pop();
            n2 = pop();
        	switch(*e){
            	case '+':
                {
            		n3 = n1 + n2;
                break;
                }
                case '-':
                {
                    n3 = n2 - n1;
                break;
                }
                case '*':
                {
            		n3 = n1 * n2;
                break;
                }
				case '/':
            	{
                    n3 = n2 / n1;
                break;
                }
			}
            push(n3);
        }
        e++;
        }
        printf("\nThe result of expression %s  =  %d\n\n",exp,pop());
        return 0;
}