C语言中的堆栈数据结构说明

我在网上遇到了这段代码，但并没有真正完全理解它。有人可以详细解释下推，弹出和窥视部分吗？这些是我最怀疑的部分。或者，甚至更好的是，如果您可以为我提供一些链接，其中详细介绍了数据结构和指针，那将是很好的。

// C program for array implementation of stack
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>

// A structure to represent a stack
struct Stack
{
    int top;
    unsigned capacity;
    int* array;
};

// function to create a stack of given capacity. It initializes size of
// stack as 0
struct Stack* createStack(unsigned capacity)
{
    struct Stack* stack = (struct Stack*) malloc(sizeof(struct Stack));
    stack->capacity = capacity;
    stack->top = -1;
    stack->array = (int*) malloc(stack->capacity * sizeof(int));
    return stack;
}

// Stack is full when top is equal to the last index
int isFull(struct Stack* stack)
{   return stack->top == stack->capacity - 1; }

// Stack is empty when top is equal to -1
int isEmpty(struct Stack* stack)
{   return stack->top == -1;  }

// Function to add an item to stack.  It increases top by 1
void push(struct Stack* stack, int item)
{
    if (isFull(stack))
        return;
    stack->array[++stack->top] = item;
    printf("%d pushed to stack\n", item);
}

// Function to remove an item from stack.  It decreases top by 1
int pop(struct Stack* stack)
{
    if (isEmpty(stack))
        return INT_MIN;
    return stack->array[stack->top--];
}

// Function to get top item from stack
int peek(struct Stack* stack)
{
    if (isEmpty(stack))
        return INT_MIN;
    return stack->array[stack->top];
}

// Driver program to test above functions
int main()
{
    struct Stack* stack = createStack(100);

    push(stack, 10);
    push(stack, 20);
    push(stack, 30);

    printf("%d popped from stack\n", pop(stack));

    printf("Top item is %d\n", peek(stack));

    return 0;
}

谢谢！！