小森-C++ Primer习题-开始

向这个世界问候

#include 

int main(void) {

	std::cout << "Hello world" << std::endl;
	return 0;
}

Hello world

简单的运算

#include 

int main(void) {
	//定义存储输入的变量
	int num1;
	int num2;

	std::cout << "请输入两个数:";
	//输入两个数
	std::cin >> num1 >> num2;
	
	//输出结果
	std::cout << "将两个数相加:[" << num1 + num2 << "]" << std::endl;

	return 0;
}

请输入两个数:  1 1
将两个数相加:[2];

计算 从50 到100 的和

#include 

int main(void) {

	int i = 50;//
	int sum = 0;

	while (i<=100){

		sum += i;
		i++;
	}

	std::cout << "从50 到100 的和为 :" << sum << std::endl;


	return 0;
}

循环逆序输出10到0的数

int main(void) {

	int i = 10;
	int sum = 0;

	while (i>=0){

		std::cout << i << std::endl;
		i--;
	}


	return 0;
}

输出这两个整数所指定的范围内的所有整数(while)

#include 

int main(void) {

	int num1;
	
	int num2;
	
	std::cout << "请输入两个数:";
	std::cin >> num1 >> num2;
	if (num1>num2){

		while (num1>=0)	{
			std::cout << num1 << " ";
			num1--;
		}

	}else {
		while (num1<=num2){
			std::cout << num1 << " ";
			num1++;
		}
	}
	std::cout << std::endl;

	return 0;
}

计算 从50 到100 的和(for)

#include 

int main(void) {

	
	int sum = 0;

	for(int i = 50; i<=100 i+){
		sum += i;
		i++;
	}
	
	std::cout << "从50 到100 的和为 :" << sum << std::endl;

	return 0;
}

输出这两个整数所指定的范围内的所有整数(for)

#include 

int main(void) {

	int num1;
	
	int num2;
	
	std::cout << "请输入两个数:";
	std::cin >> num1 >> num2;
	if (num1>num2){

		for(; num1>=num2; mum1--)	{
			std::cout << num1 << " ";
		}

	}else {
		for(; num1<=num2; mum1++)
			std::cout << num1 << " ";
		}
	}
	std::cout << std::endl;

	return 0;
}

循环输入数 ,并且求和(for)

#include 

int main(void) {

	int num;
	int sum=0;
	std::cout << "请输入数字 按Ctrl+ z键退出:";
	for (; std::cin >> num; sum += num) {
		std::cout << num << " ";
	}

	std::cout << "sum :" << sum << std::endl;
	return 0;
}

输出这两个整数所指定的范围内的所有整数(小于 by while)

#include 

int main(void) {

	int num1;
	int num2;
	
	std::cin >> num1 >> num2;
	
	if (num1<num2){
		while (num1 < num2) {
			std::cout << num1 << " ";
			num1++;
		}
	}
	else {
		while (num2 < num1) {
			std::cout << num2 << " ";
			num2++;
		}
	}

	std::cout << std::endl;
	return 0;
}

如何使用其他定义的类 并且创建对象

#include 
#include"Sales_item.h"

int main(void) {

	Sales_item item;
	std::cout << "请输入销量记录:";

	while (std::cin >> item) {
		std::cout << "ISBN ,售出本数,销售额和平均售价 " << item << std::endl;
	}

	return 0;
}

读取两个ISBN相同的sales_item对象,输出它们的和

#include 
#include"Sales_item.h"

int main(void) {

	Sales_item item1;

	Sales_item item2;
	std::cout << "请输入两条ISBN相同和销量记录:";

	std::cin >> item1 >> item2;
	if (compareIsbn(item1, item2)) {
		std::cout << "总和为 ISBN, 售出本数, 销售额和平均售价 " << item1 + item2 << std::endl;
	}
	else {
		std::cout << "不相同的ISBN!" <<std::endl;
		return -1;
	}
	
	return 0;
}

读取多条销售记录，并统计每个ISBN (每本书)有几条 销售记录。

#include 
#include"Sales_item.h"

int main(void) {
	
	Sales_item item;
	Sales_item item2;

	int num = 1;
	std::cout << "请输入若干条销售记录(ISBN ,销售,平均售价)" << std::endl;
	if (std::cin >> item) {

		while (std::cin >> item2) {
			if (compareIsbn(item, item2)) {
				++num;
			}
			else {
				std::cout << item.isbn() << "共有" << num << "条销售记录" << std::endl;
				num = 1;
				item = item2;
			}
			std::cout << item.isbn() << "共有" << num << "条销售记录" << std::endl;

		}

	}
	else{
		std::cout << "没有数据" << std::endl;
		return -1;
	}


	return 0;
}