1.7 KiB
1.7 KiB
id | challengeType | title | forumTopicId |
---|---|---|---|
5900f3ca1000cf542c50fedc | 5 | Problem 93: Arithmetic expressions | 302210 |
Description
By using each of the digits from the set, {1, 2, 3, 4}, exactly once, and making use of the four arithmetic operations (+, −, *, /) and brackets/parentheses, it is possible to form different positive integer targets.
For example,
8 = (4 * (1 + 3)) / 2
14 = 4 * (3 + 1 / 2)
19 = 4 * (2 + 3) − 1
36 = 3 * 4 * (2 + 1)
14 = 4 * (3 + 1 / 2)
19 = 4 * (2 + 3) − 1
36 = 3 * 4 * (2 + 1)
Note that concatenations of the digits, like 12 + 34, are not allowed.
Using the set, {1, 2, 3, 4}, it is possible to obtain thirty-one different target numbers of which 36 is the maximum, and each of the numbers 1 to 28 can be obtained before encountering the first non-expressible number.
Find the set of four distinct digits, a < b < c < d, for which the longest set of consecutive positive integers, 1 to n, can be obtained, giving your answer as a string: abcd.
Instructions
Tests
tests:
- text: <code>arithmeticExpressions()</code> should return a number.
testString: assert(typeof arithmeticExpressions() === 'number');
- text: <code>arithmeticExpressions()</code> should return 1258.
testString: assert.strictEqual(arithmeticExpressions(), 1258);
Challenge Seed
function arithmeticExpressions() {
return true;
}
arithmeticExpressions();
Solution
// solution required