From 49eeabe0f1f92ccb06c12f07efe0a1536332eebc Mon Sep 17 00:00:00 2001
From: Openset <openset.wang@gmail.com>
Date: Sun, 27 Jan 2019 16:07:17 +0800
Subject: [PATCH] Add: Delete Columns to Make Sorted

---
 .../delete_columns_to_make_sorted.go          | 13 ++++++++
 .../delete_columns_to_make_sorted_test.go     | 30 +++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/problems/delete-columns-to-make-sorted/delete_columns_to_make_sorted.go b/problems/delete-columns-to-make-sorted/delete_columns_to_make_sorted.go
index d217c263f..74d46d61e 100644
--- a/problems/delete-columns-to-make-sorted/delete_columns_to_make_sorted.go
+++ b/problems/delete-columns-to-make-sorted/delete_columns_to_make_sorted.go
@@ -1 +1,14 @@
 package delete_columns_to_make_sorted
+
+func minDeletionSize(A []string) int {
+	ans := 0
+	for i := 0; i < len(A[0]); i++ {
+		for j, str := range A[1:] {
+			if str[i] < A[j][i] {
+				ans++
+				break
+			}
+		}
+	}
+	return ans
+}
diff --git a/problems/delete-columns-to-make-sorted/delete_columns_to_make_sorted_test.go b/problems/delete-columns-to-make-sorted/delete_columns_to_make_sorted_test.go
index d217c263f..0172ce0ae 100644
--- a/problems/delete-columns-to-make-sorted/delete_columns_to_make_sorted_test.go
+++ b/problems/delete-columns-to-make-sorted/delete_columns_to_make_sorted_test.go
@@ -1 +1,31 @@
 package delete_columns_to_make_sorted
+
+import "testing"
+
+type caseType struct {
+	input    []string
+	expected int
+}
+
+func TestMinDeletionSize(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input:    []string{"cba", "daf", "ghi"},
+			expected: 1,
+		},
+		{
+			input:    []string{"a", "b"},
+			expected: 0,
+		},
+		{
+			input:    []string{"zyx", "wvu", "tsr"},
+			expected: 3,
+		},
+	}
+	for _, tc := range tests {
+		output := minDeletionSize(tc.input)
+		if output != tc.expected {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}