Day5

74. Search a 2D Matrix/Solution.cs

@@ -0,0 +1,30 @@
+namespace _74._Search_a_2D_Matrix;
+
+public class Solution
+{
+    public bool SearchMatrix(int[][] matrix, int target)
+    {
+        int row = SearchInsert((i) => matrix[i][0], matrix.Length, target);
+        if (row < matrix.Length && matrix[row][0] == target)
+            return true;
+        if (row > 0)
+            row--;
+        int column = SearchInsert((i) => matrix[row][i], matrix[row].Length, target);
+        return column < matrix[row].Length && matrix[row][column] == target;
+    }
+
+    private int SearchInsert(Func<int, int> getByIndex, int len, int target)
+    {
+        int l = -1;
+        int r = len;
+        while (l != r - 1)
+        {
+            int i = (r + l) / 2;
+            if (getByIndex(i) >= target)
+                r = i;
+            else
+                l = i;
+        }
+        return l + 1;
+    }
+}