Infix_to_Postfix

#include<stdio.h>
#include<conio.h>
struct node
{
char data;
struct node *link;
};
struct head
{
int count;
struct node *link;
};
void insert(struct head *heads,char x)
{
struct node *current=(struct node*)malloc(sizeof(struct node));
current->data=x;
current->link=heads->link;
heads->link=current;
heads->count=heads->count+1;
}
void delet(struct head *heads)
{int val;
struct node *current=(struct node*)malloc(sizeof(struct node));
if(heads->count==0)
{

}
else
{
current=heads->link;
val=current->data;
heads->link=current->link;
heads->count=heads->count-1;
free(current);
printf("%c",val);
}
}
int peek(struct head *heads)
{struct node *current=(struct node*)malloc(sizeof(struct node));
current=heads->link;
return current->data;
}
void display(struct head *heads)
{
struct node *current=(struct node*)malloc(sizeof(struct node));
current=heads->link;
while(current!=NULL)
{
printf("%d\t",current->data);
current=current->link;
}
}
int priority(char x)
{
if(x=='+'||x=='-')
return 2;
if(x=='*'||x=='/')
return 1;

}
void convert(char array[],struct head *heads)
{int i;
for(i=0;array[i];i++)
{
if(array[i]=='(')
insert(heads,'\0');
else if(array[i]==')')
{
delet(heads);
while(peek(heads)!='\0')
delet(heads);
}
else if(isalpha(array[i]))
{
printf("%c",array[i]);
}
else
{
char x=peek(heads);
while(heads->count!=0&&priority(x)>=priority(array[i]))
{
delet(heads);
x=peek(heads);
}
insert(heads,array[i]);
}
}
while(heads->count!=0)
delet(heads);
}
void main()
{
char array[100];
struct head *heads=(struct head*)malloc(sizeof(struct node));
clrscr();
heads->count=0;
heads->link=NULL;
printf("Enter the infix expr:");
scanf("%s",&array);
convert(array,heads);
getch();
}