fn digit_factorial(nn: usize) -> usize {
    let mut n = nn;
    let mut r = 0;
    while n != 0 {
        r += FACT[n % 10];
        n /= 10;
    }
    r
}
/// Compute the digit factorial sum of n
Compute the digit factorial sum of n
Compute the digit factorial sum of n
fn digit_factorial(nn: usize) -> usize {
    let mut n = nn;
    let mut r = 0;
    while n != 0 {
        r += FACT[n % 10];
        n /= 10;
    }
    r
}
fn digit_factorial ( nn : usize ) -> usize { let mut n = nn ; let mut r = 0 ; while n != 0 { r += FACT [ n % 10 ] ; n /= 10 ; } r }
Compute the digit factorial sum of n
Compute the digit factorial sum of n
nn
usize