leetcode

Solution to some Leetcode problems written in C++

git clone git://git.dimitrijedobrota.com/leetcode.git

1286.cpp (743B)

0 class Solution { 1 vector<int> vec; 2 const string chars; 3 string res; 4 5 bool has_next = true; 6 void shuffle() { 7 int goal = chars.size() - 1, idx = vec.size() - 1; 8 while (idx > 0 && vec[idx] == goal) 9 goal--, idx--; 10 for (int i = idx, acc = vec[idx]; i < vec.size(); i++) 11 res[i] = chars[vec[i] = ++acc]; 12 if (idx == 0 && vec[0] == goal) has_next = false; 13 } 14 15 public: 16 CombinationIterator(string chars, int len) : chars(chars), vec(len), res(len, ' ') { 17 for (int i = 0; i < len; i++) 18 res[i] = chars[vec[i] = i]; 19 vec.back()--; 20 } 21 22 string next() { 23 shuffle(); 24 return res; 25 } 26 27 bool hasNext() { return has_next; } 28 };