Digital root: Difference between revisions

=={{header|Vlang}}==

{{trans|Go}}

<lang vlang>import strconv

fn sum(ii u64, base int) int {

mut s := 0

mut i := ii

b64 := u64(base)

for ; i > 0; i /= b64 {

s += int(i % b64)

}

return s

}

fn digital_root(n u64, base int) (int, int) {

mut persistence := 0

mut root := int(n)

for x := n; x >= u64(base); x = u64(root) {

root = sum(x, base)

persistence++

}

return persistence, root

}

// Normally the below would be moved to a *_test.go file and

// use the testing package to be runnable as a regular test.

struct Test{

n string

base int

persistence int

root int

}

const test_cases = [

Test{"627615", 10, 2, 9},

Test{"39390", 10, 2, 6},

Test{"588225", 10, 2, 3},

Test{"393900588225", 10, 2, 9},

Test{"1", 10, 0, 1},

Test{"11", 10, 1, 2},

Test{"e", 16, 0, 0xe},

Test{"87", 16, 1, 0xf},

// From Applesoft BASIC example:

Test{"DigitalRoot", 30, 2, 26}, // 26 is Q base 30

// From C++ example:

Test{"448944221089", 10, 3, 1},

Test{"7e0", 16, 2, 0x6},

Test{"14e344", 16, 2, 0xf},

Test{"d60141", 16, 2, 0xa},

Test{"12343210", 16, 2, 0x1},

// From the D example:

Test{"1101122201121110011000000", 3, 3, 1},

]

fn main() {

for tc in test_cases {

n, err := strconv.common_parse_uint2(tc.n, tc.base, 64)

if err != 0 {

panic('ERROR')

}

p, r := digital_root(n, tc.base)

println("${tc.n:12} (base ${tc.base:2}) has additive persistence $p and digital root ${strconv.format_int(i64(r), tc.base)}",)

if p != tc.persistence || r != tc.root {

panic("bad result: $tc $p $r")

}

}

}</lang>

{{out}}

<pre>

627615 (base 10) has additive persistence 2 and digital root 9

39390 (base 10) has additive persistence 2 and digital root 6

588225 (base 10) has additive persistence 2 and digital root 3

393900588225 (base 10) has additive persistence 2 and digital root 9

1 (base 10) has additive persistence 0 and digital root 1

11 (base 10) has additive persistence 1 and digital root 2

e (base 16) has additive persistence 0 and digital root e

87 (base 16) has additive persistence 1 and digital root f

DigitalRoot (base 30) has additive persistence 2 and digital root q

448944221089 (base 10) has additive persistence 3 and digital root 1

7e0 (base 16) has additive persistence 2 and digital root 6

14e344 (base 16) has additive persistence 2 and digital root f

d60141 (base 16) has additive persistence 2 and digital root a

12343210 (base 16) has additive persistence 2 and digital root 1

1101122201121110011000000 (base 3) has additive persistence 3 and digital root 1

</pre>