Add the solution for LC #3698

Author: rayworks

src/main/java/org/sean/array/SubArrayMinDiffer.java

@@ -0,0 +1,64 @@
+package org.sean.array;
+
+/***
+ * 3698. Split Array With Minimum Difference
+ */
+public class SubArrayMinDiffer {
+
+    public long splitArray(int[] nums) {
+        // two pointers
+        // left ->     <- right
+        //     |
+        //   | |    |
+        // | | | ...| |
+        //
+        int n = nums.length;
+        int left = 0, right = n - 1;
+        long sumLeft = 0, sumRight = 0;
+
+        sumLeft += nums[left];
+        sumRight += nums[right];
+
+        long res = Long.MAX_VALUE;
+        while (left + 1 < right) {
+            if (nums[left + 1] > nums[left]) {
+                sumLeft += nums[left + 1];
+                left++;
+            } else {
+                break;
+            }
+        }
+
+        // move the right ptr
+        while (right - 1 > left) {
+            if (nums[right - 1] > nums[right]) {
+                sumRight += nums[right - 1];
+                right--;
+            } else {
+                break;
+            }
+        }
+
+        //System.out.printf(">>> left: %d, right: %d\n", left, right);
+        if (left + 1 == right) {
+            res = Math.min(Math.abs(sumLeft - sumRight), res);
+        } else {
+            return -1;
+        }
+
+        while (left > 0) {
+            if (nums[left] > nums[right]) {
+                sumRight += nums[left];
+                sumLeft -= nums[left];
+
+                res = Math.min(Math.abs(sumLeft - sumRight), res);
+                left--;
+                right--;
+            } else {
+                break;
+            }
+        }
+
+        return res;
+    }
+}

src/test/java/org/sean/array/SubArrayMinDifferTest.java

@@ -0,0 +1,28 @@
+package org.sean.array;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+public class SubArrayMinDifferTest {
+
+    private SubArrayMinDiffer minDiffer;
+
+    @Before
+    public void setUp() throws Exception {
+        minDiffer = new SubArrayMinDiffer();
+    }
+
+    @Test
+    public void splitArray() {
+        assertEquals(5L, minDiffer.splitArray(new int[]{
+                1, 2, 3, 5, 4, 2
+        }));
+    }
+
+    @Test
+    public void splitInvalidArray() {
+        assertEquals(-1L, minDiffer.splitArray(new int[]{3, 1, 2}));
+    }
+}