diff options
Diffstat (limited to 'other/kth_smallest_lexicographical.cpp')
-rw-r--r-- | other/kth_smallest_lexicographical.cpp | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/other/kth_smallest_lexicographical.cpp b/other/kth_smallest_lexicographical.cpp new file mode 100644 index 0000000..71478e9 --- /dev/null +++ b/other/kth_smallest_lexicographical.cpp @@ -0,0 +1,31 @@ +// 440. K-th Smallest in Lexicographical Order +#include "leetcode.h" +// given two integers 'n' and 'k', return the k'th lexicographically smallest +// integer + +class Soltuion { +public: + int findKthNumber(int n, int k) { + int curr = 1; + for (--k; k > 0;) { + int cnt = 0; + for (long long first = static_cast<long long>(curr), last = first + 1; + first <= n; first *= 10, last *= 10) + cnt += static_cast<int>((min(n + 1LL, last) - first)); + if (k >= cnt) { + ++curr; + k -= cnt; + } else { + curr *= 10; + --k; + } + } + return curr; + } +}; + +int main() { + Soltuion obj; + printf("%d\n", obj.findKthNumber(13, 2)); // expect: 10 + printf("%d\n", obj.findKthNumber(1, 1)); // expect: 1 +} |