5 （栈的应用）行编辑系统

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

typedef struct {
	char data[100];
	int top = -1;
}Stack;

bool isEmpty(Stack s) {
	if (s.top == -1) return true;
	return false;
}
bool overflow(Stack s) {
	if (s.top == 99) return true;
	return false;
}
bool push(Stack &s, char pushElem) {
	if (overflow(s)) return false;
	s.data[++s.top] = pushElem;
	return true;
}
bool pop(Stack &s, char &returnPopElem) {
	if (isEmpty(s)) return false;
	returnPopElem = s.data[s.top--];
	return true;
}

void clearStack(Stack &s) {
	s.top = -1;
}

void DestroyStack(Stack &s) {
	free(s.data);
}

void LineEdit() {
	Stack s;
	char ch = getchar();
	char ret;
	while (ch != EOF) {

		while (ch != EOF && ch != '\n') {
			switch (ch) {
			case '#':pop(s, ret); break;
			case '@' : clearStack(s); break;
			default:push(s, ch); break;
			}
		ch = getchar();
		}
		//将从栈底到栈顶的栈内字符传送至调用过程的数据区
		for (int i = 0; i <= s.top; i++) {
			printf("%c", s.data[i]);
		}
		printf("\n下一行：");
		clearStack(s);
		//此时ch可以是EOF或者\n
		if (ch != EOF) ch = getchar();

	}
	printf("\n结束");
	DestroyStack(s);
}



int main() {
	LineEdit();

	getchar();
}