6kyu Does my number look big in this
题目:
A Narcissistic Number is a number which is the sum of its own digits, each raised to the power of the number of digits.
For example, take 153 (3 digits):
1^3 + 5^3 + 3^3 = 1 + 125 + 27 = 153
and 1634 (4 digits):
1^4 + 6^4 + 3^4 + 4^4 = 1 + 1296 + 81 + 256 = 1634
The Challenge:
Your code must return true or false depending upon whether the given number is a Narcissistic number.
Error checking for text strings or other invalid inputs is not required, only valid integers will be passed into the function.
答案:
// 1
function narcissistic (value) {
return ('' + value).split('').reduce (function (p, c) {
return p + Math.pow(c, ('' + value).length)
}, 0) == value;
}
// 2
function narcissistic (value) {
var remaining = value,
digits = [],
solution = 0;
while (remaining > 0) {
digits.push(remaining % 10);
remaining = Math.floor(remaining / 10);
}
return value == digits.reduce(function (p, n) {
return p + Math.pow(n, digits.length);
}, 0);
}
// 3
function narcissistic (value) {
var value,
arr = [],
res = 0;
if (value < 10) {
return true;
} else {
arr = value.toString().split('').map(item => parseInt(item));
for (var i = 0; i < arr.length; i++) {
res += Math.pow(arr[i], arr.length);
}
return res == value ? true : false;
}
}