2022-04-15：给定一个非负数组arr，学生依次坐在0~N-1位置，每个值表示学生的安静值， 如果在i位置安置插班生，那么

fn main() {
    let arr: Vec<isize> = vec![3, 4, 2, 1, 5];
    let ret: Vec<isize> = quiet1(arr);
    println!("{:?}", ret);
}

fn quiet1(arr: Vec<isize>) -> Vec<isize> {
    if arr.len() == 0 {
        let right: Vec<isize> = Vec::new();
        return right;
    }
    let n = arr.len() as isize;
    let mut ans: Vec<isize> = Vec::new();
    for i in 0..n {
        ans.push(0);
    }
    for i in 0..n {
        let mut sum: isize = 0;
        for j in 0..i {
            sum += get_max(0, arr[j as usize] - (n - abs(i - j)));
        }
        for j in i + 1..n {
            sum += get_max(0, arr[j as usize] - (n - abs(i - j)));
        }
        ans[i as usize] = sum;
    }
    return ans;
}

fn get_max(a: isize, b: isize) -> isize {
    if a > b {
        a
    } else {
        b
    }
}

fn abs(a: isize) -> isize {
    if a < 0 {
        -a
    } else {
        a
    }
}