9.1 A child is running up a staircase with n steps, and can hop either 1 step, 2 steps, or 3 steps at a time. Implement a method to count how many possible ways the child can run up the stairs. LeetCode上的原题,请参见我之前的博客Climbing Stairs 爬梯子问题. class Solut…

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? Note: Given n will be a positive integer. Example 1: Input: 2 Output: 2 Explanation:…

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? Note: Given n will be a positive integer. Example 1: Input: 2 Output: 2 Explanation:…

题目描写叙述: 初阶:有n层的台阶,一開始你站在第0层,每次能够爬两层或者一层. 请问爬到第n层有多少种不同的方法? 进阶:假设每次能够爬两层.和倒退一层,同一个位置不能反复走,请问爬到第n层有多少种不同的方法? 解题思路: 初阶:一维动态规划.爬楼梯数目事实上是一个斐波拉契数列. 假定f[i] 表示是爬到第i层的方法,那么f[i] = f[i-1] + f[i-2] //第i层的方法数目等于第i-1层数目加上第i-2层数目. 初值:f[0] = 1, f[1] = 1. //最開始没有爬和第一…

On a staircase, the i-th step has some non-negative cost cost[i] assigned (0 indexed). Once you pay the cost, you can either climb one or two steps. You need to find minimum cost to reach the top of the floor, and you can either start from the step w…

题目: 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? Note: Given n will be a positive integer. Example 1: Input: 2 Output: 2 Explanat…

On a staircase, the i-th step has some non-negative cost cost[i] assigned (0 indexed). Once you pay the cost, you can either climb one or two steps. You need to find minimum cost to reach the top of the floor, and you can either start from the step w…

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? Note: Given n will be a positive integer. Example 1: Input: 2 Output: 2 Explanation:…

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? Note: Given n will be a positive integer. Input: 2 Output: 2 Explanation: There are…

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? 题意:有n阶楼梯,每次可以走一步或者两步,总共有多少种方法. 思路:动态规划.维护一个一维数组dp[n+1],dp[0]为n=0时的情况,dp[ i ]为到达第i阶台阶…