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 4 outputs correctly.
| 1 | int countFrom(const string& s, int i, vector<int>& memo) { |
| 2 | |
| 3 | int n = s.size(); |
| 4 | |
| 5 | if (i == n) { |
| 6 | return 1; |
| 7 | } |
| 8 | |
| 9 | if (s[i] == '0') { |
| 10 | return 0; |
| 11 | } |
| 12 | |
| 13 | if (memo[i] != -1) { |
| 14 | return memo[i]; |
| 15 | } |
| 16 | |
| 17 | int total = countFrom(s, i + 1, memo); |
| 18 | |
| 19 | if (i + 1 < n) { |
| 20 | |
| 21 | int two = (s[i] - '0') * 10 + (s[i + 1] - '0'); |
| 22 | |
| 23 | if (two <= 26) { |
| 24 | total += countFrom(s, i + 2, memo); |
| 25 | } |
| 26 | } |
| 27 | |
| 28 | memo[i] = total; |
| 29 | return total; |
| 30 | } |
| 31 | |
| 32 | int solution(const string& s) { |
| 33 | |
| 34 | if (s.empty()) { |
| 35 | return 0; |
| 36 | } |
| 37 | |
| 38 | vector<int> memo(s.size(), -1); |
| 39 | |
| 40 | return countFrom(s, 0, memo); |
| 41 | } |
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.