add 1428

fishercoder1534 · fishercoder1534 · commit d9e3da9e568f · 2020-05-03T07:50:49.000-07:00
diff --git a/README.md b/README.md
@@ -12,6 +12,7 @@ _If you like this project, please leave me a star._ &#9733;
 |1436|[Destination City](https://leetcode.com/problems/destination-city/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1436.java) | |Easy|String|
 |1432|[Max Difference You Can Get From Changing an Integer](https://leetcode.com/problems/max-difference-you-can-get-from-changing-an-integer/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1432.java) | |Medium|String|
 |1431|[Kids With the Greatest Number of Candies](https://leetcode.com/problems/kids-with-the-greatest-number-of-candies/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1431.java) | |Easy|Array|
+|1428|[Leftmost Column with at Least a One](https://leetcode.com/problems/leftmost-column-with-at-least-a-one/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1428.java) | |Medium|Array|
 |1427|[Perform String Shifts](https://leetcode.com/problems/perform-string-shifts/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1427.java) | |Easy|Array, Math|
 |1426|[Counting Elements](https://leetcode.com/problems/counting-elements/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1426.java) | |Easy|Array|
 |1423|[Maximum Points You Can Obtain from Cards](https://leetcode.com/problems/maximum-points-you-can-obtain-from-cards/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1423.java) | |Medium|Array, DP, Sliding Window|
diff --git a/src/main/java/com/fishercoder/solutions/_1428.java b/src/main/java/com/fishercoder/solutions/_1428.java
@@ -0,0 +1,40 @@
+package com.fishercoder.solutions;
+
+import com.fishercoder.common.classes.BinaryMatrix;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public class _1428 {
+    public static class Solution1 {
+        public int leftMostColumnWithOne(BinaryMatrix binaryMatrix) {
+            List<Integer> dimensions = binaryMatrix.dimensions();
+            int m = dimensions.get(0);
+            int n = dimensions.get(1);
+            List<int[]> list = new ArrayList();
+            for (int i = 0; i < m; i++) {
+                int leftMostColumn = binarySearch(i, binaryMatrix, n - 1);
+                list.add(new int[]{i, leftMostColumn});
+            }
+            Collections.sort(list, (a, b) -> a[1] - b[1]);
+            return list.get(0)[1] == 101 ? -1 : list.get(0)[1];
+        }
+
+        private int binarySearch(int row, BinaryMatrix binaryMatrix, int right) {
+            int left = 0;
+            if (binaryMatrix.get(row, right) == 0) {
+                return 101;
+            }
+            while (left < right) {
+                int mid = left + (right - left) / 2;
+                if (binaryMatrix.get(row, mid) == 0) {
+                    left = mid + 1;
+                } else {
+                    right = mid;
+                }
+            }
+            return left;
+        }
+    }
+}
diff --git a/src/test/java/com/fishercoder/_1428Test.java b/src/test/java/com/fishercoder/_1428Test.java
@@ -0,0 +1,29 @@
+package com.fishercoder;
+
+import com.fishercoder.common.classes.BinaryMatrix;
+import com.fishercoder.common.classes.BinaryMatrixImpl;
+import com.fishercoder.solutions._1428;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static junit.framework.TestCase.assertEquals;
+
+public class _1428Test {
+    private static _1428.Solution1 solution1;
+    private static BinaryMatrix binaryMatrix;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _1428.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        binaryMatrix = new BinaryMatrixImpl(new int[][]{
+                {0, 0},
+                {1, 1}
+        });
+        assertEquals(0, solution1.leftMostColumnWithOne(binaryMatrix));
+    }
+
+}
