/* stack.h */ #ifndef _stack_h #define _stack_h struct stack_record; typedef struct stack_record *stack; typedef int element_type; int is_empty( stack s ); int is_full( stack s ); stack create_stack( int max_elements ); void dispose_stack( stack s ); void make_empty( stack s ); void push( element_type x, stack s ); element_type top( stack s ); void pop( stack s ); element_type top_and_pop( stack s ); #endif
/* stack.c */ #include "stack.h" #include <stdio.h> #include <stdlib.h> #define MIN_STACK_SIZE 5 struct stack_record { int capacity; int top_of_stack; element_type *array; }; stack create_stack( int max_elements ) { stack s; if( max_elements < MIN_STACK_SIZE ) { printf( "Stack size is too small " ); exit(0); } s = malloc( sizeof( struct stack_record )); if( s == NULL ) { printf( "Out of sapce " ); exit(1); } s->array = malloc( sizeof( element_type ) * max_elements ); if( s->array == NULL ) { printf( "Out of space " ); exit(1); } s->capacity = max_elements; make_empty( s ); return s; } void dispose_stack( stack s ) { if( s != NULL ) { free( s->array ); free( s ); } } int is_empty( stack s ) { return s->top_of_stack == -1; } int is_full( stack s ) { return s->capacity == s->top_of_stack + 1; } void make_empty( stack s ) { s->top_of_stack = -1; } void push( element_type x, stack s ) { if( is_full( s ) ) { printf( "Full stack! " ); exit(0); } else s->array[++s->top_of_stack] = x; } element_type top( stack s ) { if( !is_empty( s ) ) return s->array[s->top_of_stack]; else { printf( "Empty stack " ); exit(0); } return 0; } void pop( stack s ) { if( is_empty( s ) ) { printf ("Empty stack "); exit(0); } else s->top_of_stack--; } element_type top_and_pop( stack s ) { if( !is_empty( s ) ) return s->array[s->top_of_stack--]; else { printf( "Empty stack " ); exit(0); } return 0; }
/* stack_test.c */ #include "stack.h" #include <stdio.h> int main(void) { stack s; int x; int y; int z; s = create_stack(10); push( 1, s ); push( 2, s ); push( 3, s ); x = top_and_pop( s ); y = top_and_pop( s ); z = top_and_pop( s ); printf("%d %d %d ", x, y, z); dispose_stack( s ); return 0; }
测试结果: