스택 연결리스트

#include<stdio.h> #include<stdlib.h> #include<malloc.h> typedef int element; typedef struct link{ element data; struct link * link; }stack; typedef struct top{ stack * top; }linkstack; void init(linkstack *s){ s -> top = NULL; } int is_empty(linkstack *s){ return (s->top == NULL); } void push(linkstack *s, element data){ stack *temp = (stack *)malloc(sizeof(stack)); if( temp == NULL){ fprintf(stderr,"MEMORY OMITTED"); return; } else{ temp -> data = data; temp -> link = s ->top; s->top = temp; } } element pop(linkstack *s){ if( is_empty(s) ){ fprintf(stderr, "MEMORY OMITTED"); exit(1); } else{ stack *temp = s->top; element data = temp -> data; s->top = s->top ->link; free(temp); return data; } } element peek(linkstack *s){ if( is_empty(s)){ fprintf(stderr,"MEMORY OMITTED"); exit(1); } else{ return s->top->data; } } void display_stack(linkstack *s){ stack *temp = s->top; if( is_empty(s) ){ fprintf(stderr, "MEMORY OMITTED"); exit(1); } else{ while(temp != NULL){ printf("┌──┐\n"); printf("│ %d │\n" , temp->data); printf("└──┘\n"); temp = temp ->link; } } } int main(void){ linkstack s1; linkstack *p1 = &s1; init(p1); push(p1,1); push(p1,2); push(p1,3); display_stack(p1); return 0; }