ZhouXY108/hutool
1
0
Fork 0
mirror of https://gitee.com/chinabugotech/hutool.git synced 2025-05-09 23:51:34 +08:00
Code Issues Packages Projects Releases Wiki Activity

Merge pull request #1792 from Inmord/v5-dev-optimal-comb

Browse Source 
当n = m时，C(n, m) = C(n, n) = 1。
This commit is contained in:
Golden Looly 2021-08-26 23:47:51 +08:00 committed by GitHub
commit 9bae66f219
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 1 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
hutool-core/src/main/java/cn/hutool/core/math/Combination.java
View File

@ -38,12 +38,9 @@ public class Combination implements Serializable {
* @return 组合数 * @return 组合数
*/ */
public static long count(int n, int m) { public static long count(int n, int m) {
if (0 == m) { if (0 == m || n == m) {
return 1; return 1;
} }
if (n == m) {
return NumberUtil.factorial(n) / NumberUtil.factorial(m);
}
return (n > m) ? NumberUtil.factorial(n, n - m) / NumberUtil.factorial(m) : 0; return (n > m) ? NumberUtil.factorial(n, n - m) / NumberUtil.factorial(m) : 0;
} }