[Leetcode]-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?

Hide Tags： Dynamic Programming
题目：爬楼梯，需要爬到第N步，每次你可以爬层2步或者1步，问总共有几种方法？
思路：Dynamic Programming（动态规划）

//DP(Dynamic Programming) algorithms 见算法导论//S[n] = S[n-1] + S[n-2] ; //S[1] = 1 ;//S[2] = 2 ;int climbStairs(int n) {    if( n == 0) return 0;    if( n == 1) return 1;    if( n == 2) return 2;    int one_step = 1;    int two_step = 2;    int sum_ways = 0;    int i = 0 ;    for(i=2;i<n;i++)    {        sum_ways = one_step + two_step;        one_step = two_step;        two_step = sum_ways;    }    return sum_ways;}