题解 | #计算某字符出现次数#

use std::{
    char,
    io::{self, *},
};

fn main() {
    let stdin = io::stdin();
    unsafe {
        let mut s = String::new();
        let mut flag = 0;

        for line in stdin.lock().lines() {
            let ll = line.unwrap();
            if (flag == 1) {
                let c = ll.parse::<char>().unwrap().to_ascii_lowercase();
                let res = s
                    .as_bytes()
                    .iter()
                    // .filter(|x| x.to_ascii_lowercase().eq(&c))
                    .fold(0, |acc, f| {
                        if f.to_ascii_lowercase() as char == c {
                            acc + 1
                        } else {
                            acc
                        }
                    });
                print!("{}\n", res);
                flag += 1;
            }
            if (flag == 0) {
                s.push_str(ll.as_str());
                flag += 1;
            };
            // let numbers: Vec<&str> = ll.split(" ").collect();
            // let a = numbers[0].trim().parse::<i32>().unwrap_or(0);
            // let b = numbers[1].trim().parse::<i32>().unwrap_or(0);
            // print!("{}\n", a + b);
        }
    }
}