search_a_2D_matrix

Author: hitzzc

README.md

@@ -63,6 +63,7 @@ Golang solution for leetcode. For each problem, there is a simple *_test.go to t
 #### [70. climbing stairs](https://github.com/hitzzc/go-leetcode/tree/master/climbing_stairs)
 #### [72. edit distance](https://github.com/hitzzc/go-leetcode/tree/master/edit_distance)
 #### [73. set matrix zeroes](https://github.com/hitzzc/go-leetcode/tree/master/set_matrix_zeroes)
+#### [74. search a 2D matrix](https://github.com/hitzzc/go-leetcode/tree/master/search_a_2D_matrix)
 
 
 

search_a_2D_matrix/search_a_2D_matrix.go

@@ -0,0 +1,33 @@
+package search_a_2D_matrix
+
+func searchMatrix(matrix [][]int, target int) bool {
+	if len(matrix) == 0 || len(matrix[0]) == 0 {
+		return false
+	}
+	row := -1
+	for i := 0; i < len(matrix); i++ {
+		if matrix[i][0] <= target && (i < len(matrix)-1 && matrix[i+1][0] > target || i == len(matrix)-1) {
+			row = i
+			break
+		}
+	}
+	if row == -1 {
+		return false
+	}
+	return binarySearch(matrix[row], 0, len(matrix[row])-1, target)
+}
+
+func binarySearch(array []int, i, j, target int) bool {
+	if i > j {
+		return false
+	}
+	mid := i + (j-i)/2
+	if array[mid] == target {
+		return true
+	}
+	success := binarySearch(array, i, mid-1, target)
+	if success {
+		return true
+	}
+	return binarySearch(array, mid+1, j, target)
+}