Revert "Create _881.java (fishercoder1534#147)"

This reverts commit f104be6.

Author: fishercoder1534

README.md

@@ -1034,7 +1034,7 @@ _If you like this project, please leave me a star._ ★
 | 319  |[Bulb Switcher](https://leetcode.com/problems/bulb-switcher/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_319.java)                                                                  |                                                                               |Medium| Brainteaser
 | 318  |[Maximum Product of Word Lengths](https://leetcode.com/problems/maximum-product-of-word-lengths/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_318.java)                                                                  |                                                                               |Medium| 
 | 317  |[Shortest Distance from All Buildings](https://leetcode.com/problems/shortest-distance-from-all-buildings/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_317.java)                                                                  |                                                                               |Hard| 
-| 316  |[Remove Duplicate Letters](https://leetcode.com/problems/remove-duplicate-letters/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_316.java)                                                                  |                                                                               |Medium| Stack, Recursion, Greedy
+| 316  |[Remove Duplicate Letters](https://leetcode.com/problems/remove-duplicate-letters/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_316.java)                                                                  |                                                                               |Hard| Stack, Recursion, Greedy
 | 315  |[Count of Smaller Numbers After Self](https://leetcode.com/problems/count-of-smaller-numbers-after-self/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_315.java)                                                                  |                                                                               |Hard| Tree
 | 314  |[Binary Tree Vertical Order Traversal](https://leetcode.com/problems/binary-tree-vertical-order-traversal/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_314.java)                                                                  |                                                                               |Medium| HashMap, BFS
 | 313  |[Super Ugly Number](https://leetcode.com/problems/super-ugly-number/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_313.java)                                                                  |                                                                               |Medium| 

src/main/java/com/fishercoder/solutions/1961. Check If String Is a Prefix of Array.java

@@ -57,28 +57,4 @@ public int numRescueBoats(int[] people, int limit) {
             return boats;
         }
     }
-    
-    public static class Solution2 {
-        public int numRescueBoats(int[] people, int limit) {
-            Arrays.sort(people);
-            int end = people.length - 1;
-            int start = 0;
-            int boatcount = 0;
-            while (end >= start) {
-                if (people[end] == limit) {
-                    end--;
-                    boatcount++;
-                } else if (people[end] + people[start] <= limit) {
-                    start++;
-                    end--;
-                    boatcount++;
-                } else {
-                    end--;
-                    boatcount++;
-                }
-            }
-            return boatcount;
-        }
-    }
-  
 }