C: Stack implementation - c

Question

following code for stack implementation, produces runtime-errors, although it does compile .. Can anyone help me identify find the error?
#include<stdio.h>
#define size 5
// declared a structure for stack which has an int array and top as it's members..
struct stack{
int a[size],top;
}s;
// following method pushes element 'item' in stack when called after checking if stack-overflows or not?
void push(int item){
if(s.top >= size-1)
printf("\nStack overflow..\n");
else
s.a[++s.top] = item;
}
following method pops one element when called..
int pop(){
if(s.top == -1){
printf("\n..Stack underflow..\n");
return 0;
}
return s.a[s.top];
}
// displays elements in the stack till a[top]
void display(){
int i;
for(i = s.top; i>=0; i--){
printf("\n%d", &s.a[i]);
}
}
// main() method..
int main(){
s.top = -1;
int item, choice;
char ans;
printf(" ..Stack Implementation..\n");
printf("-----------------------------");
do{
printf("\nMain Menu");
printf("\n-------------");
printf("\n 1. Push\n 2. Pop\n 3. Display\n 4. Exit\n");
printf("\n Enter your choice: ");
scanf("%d", choice);
switch(choice){
case 1:
printf("\nEnter item to be pushed: ");
scanf("%d", &item);
push(item);
break;
case 2:
pop();
break;
case 3:
display();
break;
case 4:
return 0;
}
printf("\n Want to continue? :");
scanf("%c", &ans);
}while(ans == 'Y' || ans == 'y');
return 0;
}

Answer 1

There is a small typo [I think so, as your other occurrences are correct]. Change
scanf("%d", choice);
to
scanf("%d", &choice);
Also, there is a small problem in scanf("%c", &ans);. It will suffer from the previously-pressed enter. Use
scanf(" %c", &ans); //mind the space before %
Other Issues: [Added after the edit]
printf("\n%d", &s.a[i]); -- get rid of the &, don't need that in printf()
return s.a[s.top]; should be return s.a[s.top--];