-
Notifications
You must be signed in to change notification settings - Fork 0
/
Problem38.js
53 lines (49 loc) · 1.25 KB
/
Problem38.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
/*
* Prompt: What is the largest 1 to 9 pandigital 9-digit number that can be formed as the concatenated product of an integer with (1,2, ... , n) where n > 1?
*
* Execute: node Problem38.js
*
* Answer: 932718654
*/
// Tests for 0s and repeated digits
function falsifyPandigital(n) {
n = n.toString();
if (n.indexOf("0") > -1) {
return true;
}
for (var i = 1; i < 10; i++) {
if (n.split(i).length - 1 > 1) {
return true;
}
}
// Possible pandigital
return false;
}
function isPandigital(n) {
// Expect n as an Integer, convert to String
n = n.toString();
// Split string into array of characters
n = n.split('');
// Sort array
n.sort();
// Compare array to known pandigital
return n.toString() == "1,2,3,4,5,6,7,8,9";
}
var largestConcatenatedProduct = 0;
loop:
for (var n = 1; n < 9999; n++) {
var concatenatedProduct = "";
for (var i = 1; ; i++) {
var p = n * i;
concatenatedProduct += p.toString();
if (falsifyPandigital(concatenatedProduct)) {
continue loop;
}
if (isPandigital(concatenatedProduct)) {
if (parseInt(concatenatedProduct) > largestConcatenatedProduct) {
largestConcatenatedProduct = concatenatedProduct;
}
}
}
}
console.log(largestConcatenatedProduct);