mirror of
https://github.com/krahets/hello-algo.git
synced 2024-12-26 11:26:29 +08:00
70784a1ec3
* feat(chapter_dynamic_programming): Add js and ts codes for chapter 14.1 * style(chapter_dynamic_programming): format code * refactor(chapter_dynamic_programming): remove main definition and add type * feat(chapter_backtracking): Add js and ts codes for chapter 13.3 * feat(chapter_divide_and_conquer): Add js and ts codes for chapter 12.2 * feat(chapter_divide_and_conquer): Add js and ts codes for chapter 12.3 * feat(chapter_divide_and_conquer): Add js and ts codes for chapter 12.4 * style(chapter_divide_and_conquer): fix typo * refactor: Use === instead of == in js and ts
41 lines
1 KiB
JavaScript
41 lines
1 KiB
JavaScript
/**
|
|
* File: climbing_stairs_dp.js
|
|
* Created Time: 2023-07-26
|
|
* Author: yuan0221 (yl1452491917@gmail.com)
|
|
*/
|
|
|
|
/* 爬楼梯：动态规划 */
|
|
function climbingStairsDP(n) {
|
|
if (n === 1 || n === 2) return n;
|
|
// 初始化 dp 表，用于存储子问题的解
|
|
const dp = new Array(n + 1).fill(-1);
|
|
// 初始状态：预设最小子问题的解
|
|
dp[1] = 1;
|
|
dp[2] = 2;
|
|
// 状态转移：从较小子问题逐步求解较大子问题
|
|
for (let i = 3; i <= n; i++) {
|
|
dp[i] = dp[i - 1] + dp[i - 2];
|
|
}
|
|
return dp[n];
|
|
}
|
|
|
|
/* 爬楼梯：状态压缩后的动态规划 */
|
|
function climbingStairsDPComp(n) {
|
|
if (n === 1 || n === 2) return n;
|
|
let a = 1,
|
|
b = 2;
|
|
for (let i = 3; i <= n; i++) {
|
|
const tmp = b;
|
|
b = a + b;
|
|
a = tmp;
|
|
}
|
|
return b;
|
|
}
|
|
|
|
/* Driver Code */
|
|
const n = 9;
|
|
let res = climbingStairsDP(n);
|
|
console.log(`爬 ${n} 阶楼梯共有 ${res} 种方案`);
|
|
res = climbingStairsDPComp(n);
|
|
console.log(`爬 ${n} 阶楼梯共有 ${res} 种方案`);
|
|
|