in main function add these three lines after for loop End.and remove top=POP(stack,top);
inside for loop.
while(top!=-1)
top=POP(stack,top);
printf("\n");
modified main function:
int main()
{
char string[15],ch;
int top=-1,i;
printf("Enter the infix operation: ");
gets(string);
fflush(stdin);
for(i=0;string[i]!='\0';i++)
{
ch=string[i];
if( ((ch>='a') && (ch<='z'))||((ch>='A') &&(ch<='Z')) )
{
printf("%c",string[i]);
}
else
{
ch=string[i];
top=PUSH(stack,top,ch);
}
}
while(top!=-1)
top=POP(stack,top);
printf("\n");
return 0;
}