C ++中前n个自然数之和
在此问题中，要找到前n个自然数之和，我们将找到从1到n的所有数字之和，并将它们加在一起以求和。
让我们举个例子来学习这个概念，
Input : 4 Output : 10 Explanation : Sum of first 1 natural number = 1 Sum of first 2 natural number = 1 + 2 = 3 Sum of first 3 natural number = 1 + 2 +3 = 6 Sum of first 4 natural number = 1 + 2 + 3 + 4 = 10 Sum of sum of 4 natural number = 1 + 3 + 6 + 10 = 20
示例
#include <iostream>
using namespace std;
int sumofSum(int n){
int sum = 0;
for (int i=1; i<=n; i++)
sum += i*(i+1)/2;
return sum;
}
int main(){
int n = 4;
cout<<"先加总和 "<<n<<"natural numbers is "<<sumofSum(n);
return 0;
}输出结果
先加总和 4natural numbers is 20