Type an input and write what you think is the output . Each problem is converted to Web Assembly, so any possible input will show the corresponding output. Only correct predictions count.
Locked until you have predicted 3 outputs correctly.
| 1 | void build(const string& digits, int i, string& current, |
| 2 | vector<string>& out) { |
| 3 | |
| 4 | string keys[10] = {"", "", "abc", "def", "ghi", |
| 5 | "jkl", "mno", "pqrs", "tuv", "wxyz"}; |
| 6 | |
| 7 | int n = digits.size(); |
| 8 | |
| 9 | if (i == n) { |
| 10 | out.push_back(current); |
| 11 | return; |
| 12 | } |
| 13 | |
| 14 | for (char ch : keys[digits[i] - '0']) { |
| 15 | current.push_back(ch); |
| 16 | build(digits, i + 1, current, out); |
| 17 | current.pop_back(); |
| 18 | } |
| 19 | } |
| 20 | |
| 21 | vector<string> solution(const string& digits) { |
| 22 | |
| 23 | vector<string> ans; |
| 24 | |
| 25 | if (digits.empty()) { |
| 26 | return ans; |
| 27 | } |
| 28 | |
| 29 | string current; |
| 30 | build(digits, 0, current, ans); |
| 31 | |
| 32 | return ans; |
| 33 | } |
Names have been stripped. The signature is the only clue you get for free. Compiled as C++20 with the standard headers and using namespace std; already in scope.