Mega Code Archive
Linked list stack example
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#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct node {
char *str;
struct node *next;
} STACKNODE;
void push(char *key, STACKNODE **stack);
char *pop(STACKNODE **stack);
int isempty(STACKNODE *stack);
char top(STACKNODE *stack);
int main() {
char line[1024];
char *key;
STACKNODE *stack;
stack = NULL;
while((fgets(line, 1024, stdin)) != NULL)
key = line, push(key, &stack);
while(!isempty(stack))
printf("%s", pop(&stack));
return 0;
}
char top(STACKNODE *stack) {
return *stack->str;
}
void push(char *line, STACKNODE **stack) {
STACKNODE *newnode;
newnode = (STACKNODE *)malloc(sizeof(STACKNODE));
newnode->str = strdup(line);
newnode->next = (*stack);
(*stack) = newnode;
}
char *pop(STACKNODE **stack) {
STACKNODE *oldnode;
char *key;
char *retval;
oldnode = (*stack);
key = (*stack)->str;
(*stack) = (*stack)->next;
free(oldnode);
retval = calloc(strlen(key)+1, sizeof(char));
strcpy(retval, key);
return retval;
free(retval);
}
int isempty(STACKNODE *stack) {
return stack == NULL;
}
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