add 1198

Author: fishercoder1534

README.md

@@ -15,6 +15,7 @@ _If you like this project, please leave me a star._ ★
 |1213|[Intersection of Three Sorted Arrays](https://leetcode.com/problems/intersection-of-three-sorted-arrays/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1213.java) |  |  | [:tv:](https://www.youtube.com/watch?v=zceoOrHSHNQ)|Easy||
 |1207|[Unique Number of Occurrences](https://leetcode.com/problems/unique-number-of-occurrences/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1207.java) | O(n) | O(1) | |Easy||
 |1200|[Minimum Absolute Difference](https://leetcode.com/problems/minimum-absolute-difference/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1200.java) | || [:tv:](https://www.youtube.com/watch?v=mH1aEjOEjcQ)|Easy||
+|1198|[Find Smallest Common Element in All Rows](https://leetcode.com/problems/find-smallest-common-element-in-all-rows/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1198.java) | | | |Easy||
 |1185|[Day of the Week](https://leetcode.com/problems/day-of-the-week/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1185.java) | | | |Easy||
 |1165|[Single-Row Keyboard](https://leetcode.com/problems/single-row-keyboard/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1165.java) | | | |Easy||
 |1160|[Find Words That Can Be Formed by Characters](https://leetcode.com/problems/find-words-that-can-be-formed-by-characters/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1160.java) | O(n) | O(m) | |Easy||

src/main/java/com/fishercoder/solutions/_1198.java

@@ -0,0 +1,58 @@
+package com.fishercoder.solutions;
+
+/**
+ * 1198. Find Smallest Common Element in All Rows
+ *
+ * Given a matrix mat where every row is sorted in increasing order, return the smallest common element in all rows.
+ * If there is no common element, return -1.
+ *
+ * Example 1:
+ * Input: mat = [[1,2,3,4,5],[2,4,5,8,10],[3,5,7,9,11],[1,3,5,7,9]]
+ * Output: 5
+ *
+ * Constraints:
+ * 1 <= mat.length, mat[i].length <= 500
+ * 1 <= mat[i][j] <= 10^4
+ * mat[i] is sorted in increasing order.
+ * */
+public class _1198 {
+    public static class Solution1 {
+        public int smallestCommonElement(int[][] mat) {
+            int m = mat.length;
+            int n = mat[0].length;
+            int minCommon;
+            for (int j = 0; j < n; j++) {
+                minCommon = mat[0][j];
+                int i = 1;
+                for (; i < m; i++) {//we'll start from the second row
+                    if (thisRowHasThisNumber(mat[i], minCommon)) {
+                        continue;
+                    } else {
+                        break;
+                    }
+                }
+                if (i == m) {
+                    return minCommon;
+                }
+
+            }
+            return -1;
+        }
+
+        private boolean thisRowHasThisNumber(int[] nums, int target) {
+            int left = 0;
+            int right = nums.length - 1;
+            while (left <= right) {
+                int mid = left + (right - left) / 2;
+                if (target == nums[mid]) {
+                    return true;
+                } else if (target > nums[mid]) {
+                    left = mid + 1;
+                } else {
+                    right = mid - 1;
+                }
+            }
+            return false;
+        }
+    }
+}

src/test/java/com/fishercoder/_1198Test.java

@@ -0,0 +1,29 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._1198;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class _1198Test {
+    private static _1198.Solution1 solution1;
+    private static int[][] mat;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _1198.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        mat = new int[][]{
+                {1, 2, 3, 4, 5},
+                {2, 4, 5, 8, 10},
+                {3, 5, 7, 9, 11},
+                {1, 3, 5, 7, 9}
+        };
+        assertEquals(5, solution1.smallestCommonElement(mat));
+    }
+
+}