/* main.c, test my stack of strings */
#include <stdio.h>
#include <stdlib.h>

unsigned int times( unsigned int ier, unsigned int cand );

/* interface specification for a stack of strings */
void push( const char * s ); /* push s on the stack */
const char * pop(); /* returns the top of stack and pops */
int empty(); /* reports 1 if stack empty, else 0 */

unsigned int main() { /* run the test */
    push( " zebra.\n" );
    push( " pet" );
    push( " my" );
    push( " like" );
    push( "I" );
    while( !empty() ) {
	printf( "%s", pop() );
    }
    return 0;
}

/* implement a stack of strings */

struct stack {
    const char * str; /* the string in this stack element */
    struct stack * next; /* link to rest of stack */
};

struct stack * top = NULL;

void push( const char * s ) { /* push s on the stack */
    struct stack * new = malloc( sizeof( struct stack ) );
    new->str = s;
    new->next = top;
    top = new;
}

const char * pop() { /* returns the top of stack and pops */
    const char * ret = top->str;
    struct stack * old = top;
    top = top->next;
    free( old );
    return ret;
}

int empty() { /* reports 1 if stack empty, else 0 */
    return top == NULL;
}