22afc2a0ca
Co-authored-by: Oliver Eyton-Williams <ojeytonwilliams@gmail.com> Co-authored-by: Kristofer Koishigawa <scissorsneedfoodtoo@gmail.com> Co-authored-by: Beau Carnes <beaucarnes@gmail.com>
1.7 KiB
1.7 KiB
id, challengeType, isHidden, title, forumTopicId
| id | challengeType | isHidden | title | forumTopicId |
|---|---|---|---|---|
| 5900f39c1000cf542c50feaf | 5 | false | Problem 48: Self powers | 302157 |
Description
The series, 11 + 22 + 33 + ... + 1010 = 10405071317.
Find the last ten digits of the series, 11 + 22 + 33 + ... + 10001000.
Instructions
Tests
tests:
- text: <code>selfPowers(10, 3)</code> should return a number.
testString: assert(typeof selfPowers(10, 3) === 'number');
- text: <code>selfPowers(10, 3)</code> should return 317.
testString: assert.strictEqual(selfPowers(10, 3), 317);
- text: <code>selfPowers(150, 6)</code> should return 29045.
testString: assert.strictEqual(selfPowers(150, 6), 29045);
- text: <code>selfPowers(673, 7)</code> should return 2473989.
testString: assert.strictEqual(selfPowers(673, 7), 2473989);
- text: <code>selfPowers(1000, 10)</code> should return 9110846700.
testString: assert.strictEqual(selfPowers(1000, 10), 9110846700);
Challenge Seed
function selfPowers(power, lastDigits) {
// Good luck!
return true;
}
selfPowers(1000, 10);
Solution
function selfPowers(power, lastDigits) {
let sum = 0;
const modulo = Math.pow(10, lastDigits);
for (let i = 1; i <= power; i++) {
let temp = i;
for (let j = 1; j < i; j++) {
temp *= i;
temp %= modulo;
}
sum += temp;
sum %= modulo;
}
return sum;
}