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Warning: Cannot modify header information - headers already sent by (output started at /data/wiki/inc/init.php:239) in /data/wiki/inc/httputils.php on line 29 CVBB ACM Team 2020-2021:teams:no_morning_training:shaco:知识点:动态规划
https://wiki.cvbbacm.com/
2026-06-21T01:26:25+0800CVBB ACM Team
https://wiki.cvbbacm.com/
https://wiki.cvbbacm.com/lib/exe/fetch.php?media=favicon.icotext/html2020-07-16T18:38:22+0800Anonymous (anonymous@undisclosed.example.com)2020-2021:teams:no_morning_training:shaco:知识点:动态规划:数位dp
https://wiki.cvbbacm.com/doku.php?id=2020-2021:teams:no_morning_training:shaco:%E7%9F%A5%E8%AF%86%E7%82%B9:%E5%8A%A8%E6%80%81%E8%A7%84%E5%88%92:%E6%95%B0%E4%BD%8Ddp&rev=1594895902&do=diff
用途
统计 $\text{[l,r]}$ 内符合要求的数字，一般是数位上带有xx的数字。
思路
（一般性的思路）
设 $dp[i][j]$ 为不超过 i 位的数字数位上含有数字 j 的个数 $(0\le j\le 9)$ ，则 $dp[i][j]=10\times dp[i-1][j]+10^{i-1}$ ：首先在第 i 位加上前导的数字 $0\to9$ ，即乘十，暂不考虑前导数字中对 $[a,b]$$[0,x]$$i\times dp[i-1]$$10^{i-1}$$\times$text/html2020-07-16T18:25:24+0800Anonymous (anonymous@undisclosed.example.com)2020-2021:teams:no_morning_training:shaco:知识点:动态规划:front_page
https://wiki.cvbbacm.com/doku.php?id=2020-2021:teams:no_morning_training:shaco:%E7%9F%A5%E8%AF%86%E7%82%B9:%E5%8A%A8%E6%80%81%E8%A7%84%E5%88%92:front_page&rev=1594895124&do=diff
数位dp