Give it an input and say what you think comes back. It compiles and runs for real, so a wrong guess still shows you the answer — probe as much as you like. Only correct predictions count.
Locked until you have predicted 4 outputs correctly.
| 1 | bool solveFrom(const string& s, int i, |
| 2 | const unordered_set<string>& words, |
| 3 | vector<int>& memo) { |
| 4 | int n = s.size(); |
| 5 | if (i == n) return true; |
| 6 | if (memo[i] != -1) return memo[i] == 1; |
| 7 | |
| 8 | for (int j = i + 1; j <= n; j++) { |
| 9 | string piece = s.substr(i, j - i); |
| 10 | if (words.count(piece) && solveFrom(s, j, words, memo)) { |
| 11 | memo[i] = 1; |
| 12 | return true; |
| 13 | } |
| 14 | } |
| 15 | memo[i] = 0; |
| 16 | return false; |
| 17 | } |
| 18 | |
| 19 | bool solution(const string& s, const vector<string>& words) { |
| 20 | unordered_set<string> lookup(words.begin(), words.end()); |
| 21 | vector<int> memo(s.size(), -1); |
| 22 | return solveFrom(s, 0, lookup, memo); |
| 23 | } |
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.