(M)Dynamic Programming:357. Count Numbers with Unique Digits
来源:互联网 发布:国家省市区数据库 编辑:程序博客网 时间:2024/06/06 08:34
这个题一开始没有头绪,后来看了一下别人的思路,这个题可以这样想:
设一个数组dp,dp[i]表示的n=i的时候的答案,举个例子,如果n=3,那么他等于n=2的时候不重复数字的个数加上三位数中不重复数字的个数。这样可以用动态规划:
class Solution {public: int countNumbersWithUniqueDigits(int n) { vector<int> res(n + 2, 0); res[0] = 1; res[1] = 10; for(int i = 2; i <= n; ++i) { int x = 9; for(int j = 0; j < i - 1; ++j) { x = x * (9 - j); } res[i] = res[i-1] + x; } return res[n]; }};
阅读全文
0 0
- (M)Dynamic Programming:357. Count Numbers with Unique Digits
- 【leetcode】357. Count Numbers with Unique Digits【M】【72】
- 【LeetCode】357. Count Numbers with Unique Digits
- 357. Count Numbers with Unique Digits
- LeetCode 357. Count Numbers with Unique Digits
- [leetcode] 357. Count Numbers with Unique Digits
- 357. Count Numbers with Unique Digits
- 【LeetCode】357. Count Numbers with Unique Digits
- leetcode 357. Count Numbers with Unique Digits
- leetcode 357. Count Numbers with Unique Digits
- leetcode.357. Count Numbers with Unique Digits
- 357. Count Numbers with Unique Digits
- 357. Count Numbers with Unique Digits
- 357. Count Numbers with Unique Digits
- 357. Count Numbers with Unique Digits
- 357. Count Numbers with Unique Digits
- 357. Count Numbers with Unique Digits
- 357. Count Numbers with Unique Digits
- 找到迷宫一条路的解
- Different types Server in Python
- 文章标题
- 使用ICMP协议检测网络状态
- PAT 甲级 1060. Are They Equal (25)
- (M)Dynamic Programming:357. Count Numbers with Unique Digits
- 删数问题(C语言实现)
- bzoj 1192: [HNOI2006]鬼谷子的钱袋
- 大三,2017下半年的计划
- < 笔记 > Python
- ElasticSearch
- Property动画总结
- 三分算法
- android沉浸式状态栏