C++

方法：动态规划

  1. class Solution {
  2. public:
  3.     int climbStairs(int n) {
  4.         if (n == 1) {
  5.             return 1;
  6.         } 
  8.         int one = 1, two = 2;
  9.         for (int i = 1; i < n - 1; i++) {
  10.             int temp = one;
  11.             one = two;
  12.             two += temp;
  13.         }
  15.         return two;
  16.     }
  17. };