Balanced parathesis program

[mukscoolster]

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void push(char a[], char ele, int *p);
char pop(char a[],int **q);
int check(char a[],int *p, char b1, char b2 );
int main()

{ int top =-1,i=0,x ;
char arr[100],a[100];
printf("enter the expression");

scanf("%s",&arr);
// printf("\n\n%c\n\n",arr[3]);

while(arr[i]!='\0')
{
push(a,arr[i],&top);
i++;
}
x=check(a,&top,'(',')');
x=check(a,&top,'[',']');
x=check(a,&top,'{','}');
if(x==1)
printf("balanced");
else
printf("unbalanced ");
return 0;
}
void push(char a[],char ele,int *p)
{
if((*p)>99)
{
printf("overflow!!");
return ;
}
(*p)++;
a[(*p)]=ele;
return ;
}
char pop(char a[],int **q)
{ //printf("%d\n\n",(**q));
if((**q)==-1)
{
printf("underflow");
return 0;
}
char x;
x = a[(**q)];
(**q)--;
return x;
}

int check(char a[],int *p,char b1, char b2)
{
int f1=0,f2=0,i;
while((*p)>=0)
{
if(b1==pop(a,(&p))&&b2==pop(a,(&p)))
{
f1=1;
}
else
f1=0;
}
return f1;
}

This is my code can someone help debug this ?

[AbstractionAnon]

First off, please state exactly what kind of problem you are having.

Second, your program won't execute.
check is an undefined external.
You declare check at line 6 and subsequently call it at lines 20-22, but you did not implement the function.

PLEASE USE CODE TAGS (the <> formatting button) when posting code.
http://v2.cplusplus.com/articles/jEywvCM9/
It makes it easier to read your code and it also makes it easier to respond to your post.

edit: lines 20-22, you call check three times in a row checking for (), [], and {}.
The second and third calls overlay the previous result (x).

edit: You have a simliar problem inside your while loop in check. You set f1 each time through the loop ignoring the previous condition of f1.