题解 | #等差数列#
等差数列
http://www.nowcoder.com/practice/f792cb014ed0474fb8f53389e7d9c07f
use std::io;
fn main() {
let mut s = String::new();
io::stdin().read_line(&mut s).expect("Failed to read line");
let n = s.trim().parse::<f32>().unwrap_or(2.0);
println!("{}", (2.0 + (3.0 * n - 1.0)) * n / 2.0);
}
用 Rust 刷华为机试HJ 文章被收录于专栏
用 Rust 刷 HJ100 题,只需要懂基础 Rust 语法就能看懂

