postfix calculator

i am trying a postfis calculator so far i wrote

Code:

#include<stdio.h> #include<string.h> int st[15],top=0; void push(int); int pop(void); void print(); main() {int ch; char o; char st[15],temp[15][5]; float arr[15]; int i=0,j=0,r=0,c=0,l=0,t; printf("\nEnter Expression"); fgets(st,15,stdin); printf("\nEX=%s",st); l=strlen(st); while(i<l) { one: if(st[i]=='+' || st[i]=='-' || st[i]=='*' || st[i]=='/') {o=st[i]; switch(o) {case '+': t=pop();printf("\nadding %d pushing ",t); push(pop()+t); i++;goto one;//break; case '-': t=pop(); push(t-pop()); break; case '*':t=pop(); push(t*pop()); break; case '/':t=pop(); //pop(); push(pop()/t); default:break; } } else while(st[i]!='\0' && st[i]!=' ') { temp[r][c]=st[i]; i++; c++; }temp[r][c]='\0'; printf("\npushing %d",atoi(temp[r])); push(atoi(temp[r])); r++; i++;c=0; } print(); } void push(int i) {puts("\ninpush"); if(top==15) {printf("\nStack full"); return; } st[top]=i; printf("\nst=%d,top=%d",st[top],top); top++; } int pop() { if(top==-1) { printf("\nUnder");} //print("\npop=%d",st[top]); return(st[--top]); } void print() { top--; printf("\n\n\nResult=%d\n\n",st[top]); }

iam not getting the right result though in out out ican see the result getting pushed in stack but the it pushes 0 and result is 0.
what else can i do??
Thnx.