Type: Default 1000ms 256MiB

[GESP202306 一级] 累计相加

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[GESP202306 一级] 累计相加

题目描述

输入一个正整数 nn,求形如:

1+(1+2)+(1+2+3)+(1+2+3+4)++(1+2+3+4+5++n)1+(1+2)+(1+2+3)+(1+2+3+4)+ \cdots +(1+2+3+4+5+ \cdots +n) 的累计相加。

输入格式

输入一个正整数 nn。约定 1<n1001<n \le 100

输出格式

输出累计相加的结果。

样例 #1

样例输入 #1

3

样例输出 #1

10

样例 #2

样例输入 #2

4

样例输出 #2

20

样例 #3

样例输入 #3

10

样例输出 #3

220

冯紫轩、叶冠呈、洪晟轩6月考级

Not Attended
Status
Done
Rule
Ledo
Problem
18
Start at
2025-6-15 14:00
End at
2025-7-14 18:00
Duration
700 hour(s)
Host
Partic.
5