Rust每日一练(Leetday0015) 字符串相乘、通配符匹配、跳跃游戏II

fn multiply(num1: String, num2: String) -> String {
    if num1 == "0" || num2 == "0" {
        return String::from("0");
    }
    let (m, n) = (num1.len(), num2.len());
    let mut ans_arr: Vec<i32> = vec![0; m+n];
    let num1_bytes = num1.as_bytes();
    let num2_bytes = num2.as_bytes();
    for i in (0..m).rev() {
        let x = (num1_bytes[i] - b'0') as i32;
        for j in (0..n).rev() {
            let y = (num2_bytes[j] - b'0') as i32;
            ans_arr[i + j + 1] += x * y;
        }
    }
    for i in (1..m+n).rev() {
        ans_arr[i - 1] += ans_arr[i] / 10;
        ans_arr[i] %= 10;
    }
    let mut idx = 0;
    while idx < m+n && ans_arr[idx] == 0 {
        idx += 1;
    }
    let ans_bytes: Vec<u8> = ans_arr[idx..].iter().map(|x| (*x as u8) + b'0').collect();
    String::from_utf8(ans_bytes).unwrap()
}
fn main() {
    println!("{}", multiply(String::from("123"), String::from("456")));
}

fn is_match(s: &str, p: &str) -> bool {
    let (mut si, mut pi) = (0, 0);
    let (mut s_si, mut p_si) = (0, 0);
    let s_bytes = s.as_bytes();
    let p_bytes = p.as_bytes();
    while si < s_bytes.len() {
        if pi < p_bytes.len() && (s_bytes[si] == p_bytes[pi] || p_bytes[pi] == b'?') {
            si += 1;
            pi += 1;
        } else if pi < p_bytes.len() && p_bytes[pi] == b'*' {
            s_si = si;
            p_si = pi;
            pi += 1;
        } else if p_si == usize::MAX {
            return false;
        } else {
            s_si += 1;
            si = s_si;
            pi = p_si + 1;
        }
    }
    while pi < p_bytes.len() && p_bytes[pi] == b'*' {
        pi += 1;
    }
    pi == p_bytes.len()
}
fn main() {
    println!("{}", is_match("aa", "*"));
    println!("{}", is_match("adceb", "*a*b"));
    println!("{}", is_match("acdcd", "a*c?b"));
}

fn jump(nums: Vec<i32>) -> i32 {
    let (mut end, mut max_pos, mut steps) = (0, 0, 0);
    for i in 0..nums.len()-1 {
        max_pos = max(max_pos, i + nums[i] as usize);
        if i == end {
            end = max_pos;
            steps += 1;
        }
    }
    steps
}
fn max(a: usize, b: usize) -> usize {
    if a > b {
        a
    } else {
        b
    }
}
fn main() {
    println!("{}", jump(vec![2, 3, 1, 1, 4]));
    println!("{}", jump(vec![2, 3, 0, 1, 4]));
}