揭秘 C 语言栈元素输出的奥秘385

在计算机科学中，栈是一种数据结构，它遵循后进先出 (LIFO) 原则。这意味着最后压入栈中的元素将首先弹出。本文将深入探讨如何使用 C 语言输出栈中元素的方法，包括逐个元素弹出、使用循环以及使用递归。

逐个元素弹出

最基本的方法是逐个元素弹出栈。我们可以使用弹出操作 (pop) 函数，该函数将从栈顶移除并返回元素。以下代码演示了此方法：```c
#include
#include
struct StackNode {
int data;
struct StackNode *next;
};
struct Stack {
struct StackNode *top;
};
void push(struct Stack *stack, int data) {
struct StackNode *newNode = (struct StackNode *)malloc(sizeof(struct StackNode));
newNode->data = data;
newNode->next = stack->top;
stack->top = newNode;
}
int pop(struct Stack *stack) {
if (stack->top == NULL) {
return -1; // 栈为空
}
int data = stack->top->data;
struct StackNode *temp = stack->top;
stack->top = stack->top->next;
free(temp);
return data;
}
void printStack(struct Stack *stack) {
struct StackNode *temp = stack->top;
while (temp != NULL) {
printf("%d ", temp->data);
temp = temp->next;
}
printf("");
}
int main() {
struct Stack stack;
= NULL;
push(&stack, 1);
push(&stack, 2);
push(&stack, 3);
printStack(&stack); // 输出：3 2 1
int popped_element;
while ((popped_element = pop(&stack)) != -1) {
printf("%d ", popped_element);
}
printf(""); // 输出：3 2 1
return 0;
}
```

使用循环

我们可以使用循环和弹出函数来简洁地输出栈中所有元素。以下代码演示了此方法：```c
#include
#include
struct StackNode {
int data;
struct StackNode *next;
};
struct Stack {
struct StackNode *top;
};
void push(struct Stack *stack, int data) {
struct StackNode *newNode = (struct StackNode *)malloc(sizeof(struct StackNode));
newNode->data = data;
newNode->next = stack->top;
stack->top = newNode;
}
int pop(struct Stack *stack) {
if (stack->top == NULL) {
return -1; // 栈为空
}
int data = stack->top->data;
struct StackNode *temp = stack->top;
stack->top = stack->top->next;
free(temp);
return data;
}
void printStack(struct Stack *stack) {
struct StackNode *temp = stack->top;
while (temp != NULL) {
printf("%d ", temp->data);
temp = temp->next;
}
printf("");
}
int main() {
struct Stack stack;
= NULL;
push(&stack, 1);
push(&stack, 2);
push(&stack, 3);
printStack(&stack); // 输出：3 2 1
while ( != NULL) {
printf("%d ", pop(&stack));
}
printf(""); // 输出：3 2 1
return 0;
}
```

使用递归

递归是一种使用函数调用函数本身的技术。我们可以使用递归来遍历栈并打印其元素。以下代码演示了此方法：```c
#include
#include
struct StackNode {
int data;
struct StackNode *next;
};
struct Stack {
struct StackNode *top;
};
void push(struct Stack *stack, int data) {
struct StackNode *newNode = (struct StackNode *)malloc(sizeof(struct StackNode));
newNode->data = data;
newNode->next = stack->top;
stack->top = newNode;
}
int pop(struct Stack *stack) {
if (stack->top == NULL) {
return -1; // 栈为空
}
int data = stack->top->data;
struct StackNode *temp = stack->top;
stack->top = stack->top->next;
free(temp);
return data;
}
void printStackRecursive(struct StackNode *top) {
if (top == NULL) {
return;
}
printf("%d ", top->data);
printStackRecursive(top->next);
}
int main() {
struct Stack stack;
= NULL;
push(&stack, 1);
push(&stack, 2);
push(&stack, 3);
printStackRecursive(); // 输出：3 2 1
return 0;
}
```