Linked list stack example #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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