Problems › JavaScript › games
Score dice pairs
A dice game awards points from matching pairs. For each face value that appears more than once, every pair of matching dice contributes the face value to the total score.
- Count how many times each face value appears.
- A face appearing k times forms k*(k-1)/2 pairs.
- Each pair scores the face value.
- If no value repeats, the score is zero.
dicePairsScore(dice: list<int>) → int
Where you start
function dicePairsScore(dice) {
}Worked examples
| Call | Result |
|---|---|
dicePairsScore([2,3,2,5,3]) | 5 |
dicePairsScore([6,6,6]) | 18 |
dicePairsScore([1,2,3]) | 0 |
dicePairsScore([4,4,4,4]) | 24 |
Hint
Count frequencies, then for each face with two or more occurrences add value * count * (count - 1) / 2.
Reference solution in JavaScript
function dicePairsScore(dice) {
const freq = {};
for (const d of dice) freq[d] = (freq[d] || 0) + 1;
let sum = 0;
for (const v in freq) {
const k = freq[v];
if (k >= 2) sum += Number(v) * k * (k - 1) / 2;
}
return sum;
}