第一单元
练习 1.1
编写程序，在标准输出上打印Hello, World。
#include <iostream>int main(int argc, const char * argv[]) {std::cout << "Hello, ceshi!\n";return 0;
}
练习 1.2
我们编写程序使用乘法运算符*，来打印两个数的积。
#include <iostream>int main(int argc, const char * argv[]) {int a,b;std::cout<<"请输入两个数字：\n";std::cin>>a>>b;std::cout << "数字 " << a << " and " << b<< " 乘积是 " << a * b << std::endl;return 0;
}
练习 1.3
我们将所有的输出操作放在一条很长的语句中，重写程序，将每个运算对象的打印操作放在一条独立的语句中。
#include <iostream>int main()
{std::cout << "Enter two numbers:" << std::endl;int v1 = 0, v2 = 0;std::cin >> v1 >> v2;std::cout << "The product of ";std::cout << v1;std::cout << " and ";std::cout << v2;std::cout << " is ";std::cout << v1 * v2;std::cout << std::endl;
}
练习 1.4
合法的注释语句
#include <iostream>int main(int argc, const char * argv[]) {std::cout << "/*";std::cout << "*/";std::cout << /* "*/" */";std::cout << /* "*/" /* "/*" */;return 0;
}
练习 1.5
使用while循环将50到100整数相加
#include <iostream>int main(int argc, const char * argv[]) {int sum = 0, val = 50;while (val <= 100){sum += val;val += 1;}std::cout << "Sum of 50 to 100 inclusive is "<< sum << std::endl;return 0;
}
练习 1.6
使用 for 循环将50到100整数相加
#include <iostream>int main(int argc, const char * argv[]) {int sum = 0, val = 50;for(;val<=100;val++){sum += val;}std::cout << "Sum of 50 to 100 inclusive is "<< sum << std::endl;return 0;
}练习 1.7
编写程序，从cin读取一组数，输出其和
#include <iostream>int main(int argc, const char * argv[]) {int sum = 0, val;for (int i=1;i<=10;i++){std::cout<< "请输入第" << i << "个数："<<std::endl;std::cin>>val;sum += val;}std::cout << "输入的10个数字之和是："<< sum << std::endl;return 0;
}
练习 1.8
打印一个范围内的数），使其能处理用户输入的第一个数比第二个数小的情况
#include <iostream>int main()
{int s = 0, e = 0;std::cout << "请输入两个数字: ";std::cin >> s >> e;if (s <= e) {while (s <= e){std::cout << s << " ";++s;}std::cout << std::endl;}else{std::cout << "输入不合法!!!";}
}
】)
