#include
using namespace std;
int main()
{
int n, sum;
cout << "请输入N:" << endl;
cin >> n;
for (int i = 1; i < n; i++)
{
for (int j = 1; j < i; j++)
{
sum = sum + j;
}
}
cout << "结果为:" << sum;
system("pause");
return 0;
}
#include
using namespace std;
int main()
{
int n, sum;
cout << "请输入N:" << endl;
cin >> n;
for (int i = 1; i < n; i++)
{
for (int j = 1; j < i; j++)
{
sum = sum + j;
}
}
cout << "结果为:" << sum;
system("pause");
return 0;
}
错误的地方:
1、首先include后面没有包含
2、sum 值没有初始化;
3、sum是局部变量,for语句执行完成就释放了,应该定位为static变量
4、for循环中应添加相等的情况,也就是注意边界。
正常程序如下:
#include
using namespace std;
int main()
{
int n;
static int sum=1;
cout << "请输入N:" << endl;
cin >> n;
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= i; j++)
{
sum = sum + j;
}
}
cout << "结果2为:" << sum;
system("pause");
return 0;
}