2

Author: kedebug

Searcha2DMatrix/Searcha2DMatrix.cpp

@@ -0,0 +1,41 @@
+class Solution {
+public:
+    bool searchMatrix(vector<vector<int>>& matrix, int target) {
+        // Start typing your C/C++ solution below
+        // DO NOT write int main() function
+        if (matrix.empty()) return false;
+        int lf = 0;
+        int rt = matrix.size() - 1;
+        int column = matrix[0].size();
+        while (lf <= rt) {
+            int m = (lf + rt) / 2;
+            if (target < matrix[m][0]) {
+                rt = m - 1;
+            }
+            else if (target > matrix[m][column-1]) {
+                lf = m + 1;
+            }
+            else {
+                return isValid(matrix[m], target);
+            }
+        }
+        return false;
+    }
+    bool isValid(vector<int>& row, int target) {
+        int lf = 0;
+        int rt = row.size() - 1;
+        while (lf <= rt) {
+            int m = (lf + rt) / 2;
+            if (target == row[m]) {
+                return true;
+            }
+            else if (target > row[m]) {
+                lf = m + 1;
+            }
+            else {
+                rt = m - 1;
+            }
+        }
+        return false;
+    }
+};