Update README.md

Rain120 · web-flow · commit f3e44177f1ab · 2018-05-26T11:50:17.000+08:00
diff --git a/src/algorithms/math/factorial/README.md b/src/algorithms/math/factorial/README.md
@@ -3,7 +3,7 @@
 In mathematics, the factorial of a non-negative integer `n`, 
 denoted by `n!`, is the product of all positive integers less 
 than or equal to `n`. For example:
-
+在数学中，由n！表示的非负整数n的阶乘是小于或等于n的所有正整数的乘积。例如
 ```
 5! = 5 * 4 * 3 * 2 * 1 = 120
 ```
