update 740

Author: fishercoder1534

Diff for: src/main/java/com/fishercoder/solutions/_740.java

@@ -1,5 +1,7 @@
 package com.fishercoder.solutions;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.TreeMap;
 
 public class _740 {
@@ -59,4 +61,33 @@ public int deleteAndEarn(int[] nums) {
             return curr;
         }
     }
+
+    public static class Solution3 {
+        //use DP, this is basically the same code as https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/_3186.java
+        //except here it's current - 1, in the above it's current - 2
+        public int deleteAndEarn(int[] nums) {
+            TreeMap<Integer, Integer> treeMap = new TreeMap<>();
+            for (int num : nums) {
+                treeMap.put(num, treeMap.getOrDefault(num, 0) + 1);
+            }
+            List<Integer> sortedList = new ArrayList<>(treeMap.keySet());
+            int[] dp = new int[sortedList.size()];
+            dp[0] = sortedList.get(0) * treeMap.get(sortedList.get(0));
+            for (int i = 1; i < sortedList.size(); i++) {
+                int current = sortedList.get(i);
+                int currentTotal = current * treeMap.get(current);
+                int j = i - 1;
+                //we keep going to the left of the sorted list until we find a value that's not in the range of current - 1 if possible
+                while (j >= 0 && sortedList.get(j) >= current - 1) {
+                    j--;
+                }
+                if (j >= 0) {
+                    dp[i] = Math.max(dp[i - 1], currentTotal + dp[j]);
+                } else {
+                    dp[i] = Math.max(dp[i - 1], currentTotal);
+                }
+            }
+            return dp[dp.length - 1];
+        }
+    }
 }

Diff for: src/test/java/com/fishercoder/_740Test.java

@@ -1,29 +1,37 @@
 package com.fishercoder;
 
 import com.fishercoder.solutions._740;
-import org.junit.BeforeClass;
-import org.junit.Test;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public class _740Test {
-  private static _740.Solution1 solution1;
-  private static int[] nums;
+    private static _740.Solution1 solution1;
+    private static _740.Solution2 solution2;
+    private static _740.Solution3 solution3;
+    private static int[] nums;
 
-  @BeforeClass
-  public static void setup() {
-    solution1 = new _740.Solution1();
-  }
+    @BeforeEach
+    public void setup() {
+        solution1 = new _740.Solution1();
+        solution2 = new _740.Solution2();
+        solution3 = new _740.Solution3();
+    }
 
-  @Test
-  public void test1() {
-    nums = new int[] {3, 4, 2};
-    assertEquals(6, solution1.deleteAndEarn(nums));
-  }
+    @Test
+    public void test1() {
+        nums = new int[]{3, 4, 2};
+        assertEquals(6, solution1.deleteAndEarn(nums));
+        assertEquals(6, solution2.deleteAndEarn(nums));
+        assertEquals(6, solution3.deleteAndEarn(nums));
+    }
 
-  @Test
-  public void test2() {
-    nums = new int[] {2, 2, 3, 3, 3, 4};
-    assertEquals(9, solution1.deleteAndEarn(nums));
-  }
+    @Test
+    public void test2() {
+        nums = new int[]{2, 2, 3, 3, 3, 4};
+        assertEquals(9, solution1.deleteAndEarn(nums));
+        assertEquals(9, solution2.deleteAndEarn(nums));
+        assertEquals(9, solution3.deleteAndEarn(nums));
+    }
 }