class Solution { public: int rectCover(int n) { if (n == 0 || n == 1 || n == 2) return n; int a = 1; int b = 2; int sum; for (int i = 3; i <= n; ++i) { sum = a + b; a = b; b = sum; } return sum; } };
class Solution { public: int rectCover(int n) { if (n == 0 || n == 1 || n == 2) return n; int a = 1; int b = 2; int sum; for (int i = 3; i <= n; ++i) { sum = a + b; a = b; b = sum; } return sum; } };