LeetCode力扣 70. 爬樓梯 Climbing Stairs 題解代碼 JavaScript

問題 https://leetcode-cn.com/problems/climbing-stairs/

練習使用JavaScript解答

/**
 * @param {number} n
 * @return {number}
 */
var climbStairs = function(n) {
    if(n == 1)
        return 1;
    var i, f1=1,f2=1,f3;
    for(i=2;i<=n;++i) {
        f3 = f1 + f2;
        f1 = f2;
        f2 = f3;
    }
    return f3;
};