앞 전 문제와 비슷하지만 이번엔 경우의수를 구해보는 문제.
문제
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: There are two ways to climb to the top.
- 1 step + 1 step
- 2 steps Example 2:
Input: 3 Output: 3 Explanation: There are three ways to climb to the top.
- 1 step + 1 step + 1 step
- 1 step + 2 steps
- 2 steps + 1 step
풀이
생각의 흐름
/**
* @param {number} n
* @return {number}
*/
var climbStairs = function(n) {
const dp = [];
for (let i = 1; i <= n; i++) {
if (i <= 2) {
dp[i] = i;
} else {
dp[i] = dp[i - 2] + dp[i - 1];
}
}
return dp[n];
};