题解 | #截取字符串#
截取字符串
https://www.nowcoder.com/practice/a30bbc1a0aca4c27b86dd88868de4a4a
use std::io::{self, *}; fn main() { let stdin = io::stdin(); let mut input = String::new(); stdin.read_line(&mut input).unwrap(); let mut num = String::new(); stdin.read_line(&mut num).unwrap(); let num = num.trim().parse::<usize>().unwrap(); input.truncate(num); println!("{}",input); }