输入一组数，输出其中有多少个负数。

1.输入一组数，输出其中有多少个负数。

 

程序代码如下：

#include <iostream>

int main()
{
 int sum = 0, value;
 
 std::cout << "Please input your numbers [End with CRTL+D] :" << std::endl;
 while (std::cin >> value) {
  if (value < 0) {
   sum++;
  }
 }

 std::cout << "There is " << sum << " negative numbers ." << std::endl;

 return 0;
}

 

2. 提示用户输入两个数，并将这两个数之间的每个数输出。

 

程序代码如下：

#include <iostream>

int main()
{
 int v1, v2;
 std::cout << "Please input v1 and v2 : " << std::endl;
 std::cin >> v1 >> v2 ;
 std::cout << "The number between the " << v1 << " and " << v2 << std::endl;
 
 int lower, upper;
 if (v1 <=v2) {
  lower = v1;
  upper = v2;
 } else {
  lower = v2;
  upper = v1;
 }

 int value = lower;
 while (value < upper-1) {
  ++value;
  std::cout << value << " ";
 }

 return 0;
}

 

3.输入两个数，再求两个数之间的数之和

 

程序代码如下：

#include <iostream>

int main()
{
 int v1, v2;

 std::cout << "Please input v1 and v2 :" << std::endl;
 std::cin >> v1 >> v2;

 int upper, lower;
 if ( v1 <= v2) {
  upper = v2;
  lower = v1;
 } else {
  upper = v1;
  lower = v2;
 }

 int sum = 0;
 for (int i = lower+1; i <= upper-1; i++) {
  sum +=i;
 }
 std::cout << "The sum of the numbers between " << v1 << " and " << v2 << " is " << sum <<std::endl;
 return 0;
}