Own digits power sum: Difference between revisions
→Faster
(→Faster) |
|||
Line 1,828:
===Faster===
{{trans|
fn main() {
let mut powers = vec![0, 1, 4, 9, 16, 25, 36, 49, 64, 81];
println!("Own digits power sums for N = 3 to 9 inclusive:");
for n in 3..=9 {
for d in 2..=9 {
powers[d] *= d;
}
let mut i = 10u64.pow(n - 1);
let max = i * 10;
let mut last_digit = 0;
let mut sum = 0;
let mut digits: Vec<u32>;
while i < max {
if last_digit == 0 {
digits = i.to_string()
.chars()
.map(|c| c.to_digit(10).unwrap())
.collect();
sum = digits.iter().map(|&d| powers[d as usize]).sum();
} else if last_digit == 1 {
sum += 1;
} else {
sum += powers[last_digit as usize] - powers[(last_digit - 1) as usize];
}
if sum == i.try_into().unwrap() {
println!("{}", i);
if last_digit == 0 {
println!("{}", i + 1);
}
i += 10 - last_digit;
last_digit = 0;
} else if sum > i.try_into().unwrap() {
i += 10 - last_digit;
last_digit = 0;
} else if last_digit < 9 {
i += 1;
last_digit += 1;
} else {
i += 1;
last_digit = 0;
}
}
}
}
<pre>
Own digits power sums for N = 3 to 9 inclusive:
153
370
371
407
1634
8208
9474
54748
92727
93084
548834
1741725
4210818
9800817
9926315
24678050
24678051
88593477
146511208
472335975
534494836
912985153
<pre>
=={{header|Sidef}}==
| |||