用C++求1到N的和，请各位豪杰帮忙下。。。谢谢啦

Sn=(1+N)*N/2
输入N 输出Sn

int n;
    long Sum=0;
    cout<<"Please input N :";
    cin>>n;
    for (int i=1;i<=n;++i)
    {
        Sum += i;
    }

(上底+下底)*高/2,呵呵这个好!

#include <iostream>
#include <stdio.h>
using namespace std;
int main()
{
 int x,j,sum=0;
cout<<"please enter a number: ";
cin>>x;
cout<<x;
cout<<"\n";
for(j=0;j<=x;j++)
    sum+=j;
cout<<sum;
cout<<"\n";
return 0;
}

我晕   谢伟  你可真够恨的

都被说了6

应该很容易吧这个

#include <iostream>
#include <stdio.h>
using namespace std;
int main()
{
int x=1,j,sum=0;
cout<<"请输入一个数: ";
cin>>x;
cout<<x;
cout<<"\n";
for(j=0;j<=x;j++)
    sum+=j;
cout<<sum;
cout<<"\n";
return 0;
}

#include <iostream>
using namespace std;

int main()
{
int temp = -1;//默认设为-1
int sum = 0;//和
cout << "请输入一个数: ";
cin >> temp;
for(int i = 0; i < temp; i++)
    sum = sum + i + 1; //累加
cout << sum << endl; //输出结果
return 0;
}