leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
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0754.cpp (380B)

      1 class Solution {
      2   public:
      3     int reachNumber(int target) const {
      4         target = abs(target);
      5 
      6         const long long n = ceil((sqrt(1 + 8.0 * target) - 1.0) / 2);
      7         const long long sum = n * (n + 1) / 2;
      8 
      9         if (sum == target) return n;
     10         const long long res = sum - target;
     11 
     12         if (res % 2 == 0) return n;
     13         return n + (n % 2 == 1) + 1;
     14     }
     15 };