rust_basic_code/md_file/3练习.md

1. 华氏度和摄氏度互相转化

use std::io;

fn main() {
    println!("请输入您的体温: ");
    let mut temp = String::new();
    io::stdin()
        .read_line(&mut temp)
        .expect("输入数据有误");
    let temp: f64 = temp.trim().parse().expect("类型转换失败");

    println!("请输入温度单位(F或C)：（若无特殊设置，默认大于50度为华氏度）:");
    let mut unit = String::new();
    io::stdin()
        .read_line(&mut unit)
        .expect("输入数据有误");
// 也可以通过去字符串，我直接true false了。
    let unit2:bool = match unit.trim(){
        "F"=>true,
        "C"=>false,
        _=>{
            if temp > 50.0 {
                println!("使用华氏温度单位(F)");
                true
            }else {
                println!("使用摄氏温度单位(C)");
                false
            }
        }
    };

    println!("FFF is: {}", temp);
    println!("type is: {}", unit2);

    let res = trans(temp, unit2);
    println!("res is: {}", res);
}

fn trans(temp:f64, is_fahrenheit:bool)->f64{
    if is_fahrenheit{
        (temp-32.0)*5.0/9.0
    }else {
        temp*9.0/5.0 +32.0
    }
}

2. 生成第n个斐波那契数

use std::io;

fn main() {
    println!("请输入你要查的队列下标");
    let mut n = String::new();
    io::stdin()
        .read_line(&mut n)
        .expect("数据输入有误");

    let n:i32 = n.trim().parse().expect("类型转换失败");

    let mut a = 0;
    let mut b = 1;

    for i in 0..n{
        let c = a+b;
        a = b;
        b = c;
    }
    println!("res is: {}", a);
}

3. 圣诞节的十二天

fn main() {
    let days = ["first", "second", "third", "fourth", "fifth", "sixth",
        "seventh", "eighth", "ninth", "tenth", "eleventh", "twelfth"];
    let gifts = ["A partridge in a pear tree.", "Two turtle doves,",
        "Three French hens,", "Four calling birds,",
        "Five golden rings,", "Six geese a-laying,",
        "Seven swans a-swimming,", "Eight maids a-milking,",
        "Nine ladies dancing,", "Ten lords a-leaping,",
        "Eleven pipers piping,", "Twelve drummers drumming,"];

    for i in 0..12{
        println!("On the {} day of Christmas, \nmy true love sent to me", days[i]);
        for j in (0..=i).rev(){
            println!("{}",gifts[j]);
        }
        println!();
    }

    println!("Hello, world!");
}