Leetcode-70 Climbing Stairs
#70. Climbing Stairs
You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
题解:这道题属于动态规划的题,类似于斐波那契数列,所以采用非递归的方式来解。当楼梯只有一级时,显然只有一种方法,即f(1)=1;当楼梯有两级时,显然有两种方法,即f(2)=2;当楼梯有n级时,f(n) = f(n-1) + f(n-2);
class Solution { public: int climbStairs(int n) { if(n<=2) { return n; } int array[n+1]={0}; array[1]=1; array[2]=2; for(int i=3;i<=n;i++) { array[i]=array[i-1]+array[i-2]; } return array[n]; } };