1+ /**
2+ * https://leetcode.com/problems/climbing-stairs/#/description
3+ *
4+ * You are climbing a stair case. It takes n steps to reach to the top.
5+ * Each time you can either climb 1 or 2 steps.
6+ * In how many distinct ways can you climb to the top?
7+ *
8+ * Note: Given n will be a positive integer.
9+ *
10+ * 答案:
11+ *
12+ * https://leetcode.com/articles/climbing-stairs/
13+ */
14+
15+ /**
16+ *@param {number } n
17+ *@return {number }
18+ */
19+ var climbStairs = function ( n ) {
20+ if ( n < 2 ) return 1 ;
21+ return climbStairs ( n - 1 ) + climbStairs ( n - 2 ) ;
22+ } ;
23+
24+ /**
25+ *@param {number } n
26+ *@return {number }
27+ */
28+ var climbStairs2 = function ( n ) {
29+ var ways = [ 1 , 1 ] ;
30+ for ( var i = 2 ; i <= n ; i ++ ) {
31+ ways [ i ] = ways [ i - 1 ] + ways [ i - 2 ] ;
32+ }
33+ return ways [ n ] ;
34+ } ;
35+
36+ console . log ( climbStairs ( 1 ) ) ;
37+ console . log ( climbStairs ( 2 ) ) ;
38+ console . log ( climbStairs ( 3 ) ) ;
39+ console . log ( climbStairs ( 4 ) ) ;
40+
41+ console . log ( '==============' ) ;
42+
43+ console . log ( climbStairs2 ( 1 ) ) ;
44+ console . log ( climbStairs2 ( 2 ) ) ;
45+ console . log ( climbStairs2 ( 3 ) ) ;
46+ console . log ( climbStairs2 ( 4 ) ) ;
