add 1981

fishercoder1534 · fishercoder1534 · commit 1d7717428434 · 2021-08-22T10:11:11.000-07:00
diff --git a/README.md b/README.md
@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ &#9733;
 
 |  #  |      Title     |   Solutions   | Video  | Difficulty  | Tag                  
 |-----|----------------|---------------|--------|-------------|-------------
+|1981|[Minimize the Difference Between Target and Chosen Elements](https://leetcode.com/problems/minimize-the-difference-between-target-and-chosen-elements/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1981.java) ||Medium|DP|
 |1980|[Find Unique Binary String](https://leetcode.com/problems/find-unique-binary-string/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1980.java) ||Medium||
 |1979|[Find Greatest Common Divisor of Array](https://leetcode.com/problems/find-greatest-common-divisor-of-array/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1979.java) ||Easy||
 |1974|[Minimum Time to Type Word Using Special Typewriter](https://leetcode.com/problems/minimum-time-to-type-word-using-special-typewriter/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1974.java) ||Easy||
diff --git a/src/main/java/com/fishercoder/solutions/_1981.java b/src/main/java/com/fishercoder/solutions/_1981.java
@@ -0,0 +1,34 @@
+package com.fishercoder.solutions;
+
+public class _1981 {
+    public static class Solution1 {
+        /**
+         * creidt: https://leetcode.com/problems/minimize-the-difference-between-target-and-chosen-elements/discuss/1418614/Java-dp-code-with-proper-comments-and-explanation
+         */
+        int ans = Integer.MAX_VALUE;
+        boolean[][] dp;
+
+        public int minimizeTheDifference(int[][] mat, int target) {
+            dp = new boolean[mat.length][4900];//we use 4900 due to the contraints in this problem: 70 * 70 = 4900
+            memo(mat, 0, 0, target);
+            return ans;
+        }
+
+        private void memo(int[][] mat, int row, int sum, int target) {
+            if (dp[row][sum]) {
+                return;
+            }
+            if (row == mat.length - 1) {
+                for (int i = 0; i < mat[0].length; i++) {
+                    ans = Math.min(ans, Math.abs(sum + mat[row][i] - target));
+                }
+                dp[row][sum] = true;
+                return;
+            }
+            for (int i = 0; i < mat[0].length; i++) {
+                memo(mat, row + 1, sum + mat[row][i], target);
+            }
+            dp[row][sum] = true;
+        }
+    }
+}
diff --git a/src/test/java/com/fishercoder/_1981Test.java b/src/test/java/com/fishercoder/_1981Test.java
@@ -0,0 +1,32 @@
+package com.fishercoder;
+
+import com.fishercoder.common.utils.CommonUtils;
+import com.fishercoder.solutions._1981;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class _1981Test {
+    private static _1981.Solution1 solution1;
+
+    @BeforeEach
+    public static void setup() {
+        solution1 = new _1981.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        assertEquals(0, solution1.minimizeTheDifference(CommonUtils.convertLeetCodeIrregularLengths2DArrayInputIntoJavaArray("[1,2,3],[4,5,6],[7,8,9]"), 13));
+    }
+
+    @Test
+    public void test2() {
+        assertEquals(94, solution1.minimizeTheDifference(CommonUtils.convertLeetCodeIrregularLengths2DArrayInputIntoJavaArray("[1],[2],[3]"), 100));
+    }
+
+    @Test
+    public void test3() {
+        assertEquals(1, solution1.minimizeTheDifference(CommonUtils.convertLeetCodeIrregularLengths2DArrayInputIntoJavaArray("[1,2,9,8,7]"), 6));
+    }
+
+}
