更新题目描述

Algorithms/41.First-Missing-Positive/README.md

@@ -4,18 +4,27 @@
 
 Given an unsorted integer array, find the smallest missing positive integer.
 
-Example 1:
+Example 1:  
 
-Input: [1,2,0]
-Output: 3
-Example 2:
+```
+Input: [1,2,0]  
+Output: 3  
+```
 
-Input: [3,4,-1,1]
-Output: 2
-Example 3:
+Example 2:  
 
-Input: [7,8,9,11,12]
-Output: 1
-Note:
+```
+Input: [3,4,-1,1]  
+Output: 2  
+```
+
+Example 3:  
+
+```
+Input: [7,8,9,11,12]  
+Output: 1  
+```
+
+Note:  
 
 Your algorithm should run in O(n) time and uses constant extra space.