--- id: 5900f39c1000cf542c50feaf title: 'Problem 48: Self powers' challengeType: 5 forumTopicId: 302157 dashedName: problem-48-self-powers --- # --description-- The series, 11 + 22 + 33 + ... + 1010 = 10405071317. Find the last ten digits of the series, 11 + 22 + 33 + ... + 10001000. # --hints-- `selfPowers(10, 3)` should return a number. ```js assert(typeof selfPowers(10, 3) === 'number'); ``` `selfPowers(10, 3)` should return 317. ```js assert.strictEqual(selfPowers(10, 3), 317); ``` `selfPowers(150, 6)` should return 29045. ```js assert.strictEqual(selfPowers(150, 6), 29045); ``` `selfPowers(673, 7)` should return 2473989. ```js assert.strictEqual(selfPowers(673, 7), 2473989); ``` `selfPowers(1000, 10)` should return 9110846700. ```js assert.strictEqual(selfPowers(1000, 10), 9110846700); ``` # --seed-- ## --seed-contents-- ```js function selfPowers(power, lastDigits) { return true; } selfPowers(1000, 10); ``` # --solutions-- ```js 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; } ```