add 2075

Author: fishercoder1534

README.md

@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ ★
 
 |  #  |      Title     |   Solutions   | Video  | Difficulty  | Tag                  
 |-----|----------------|---------------|--------|-------------|-------------
+|2075|[Decode the Slanted Ciphertext](https://leetcode.com/problems/decode-the-slanted-ciphertext/)|[Java](../master/src/main/java/com/fishercoder/solutions/_2075.java) ||Medium||
 |2074|[Reverse Nodes in Even Length Groups](https://leetcode.com/problems/reverse-nodes-in-even-length-groups/)|[Java](../master/src/main/java/com/fishercoder/solutions/_2074.java) ||Medium||
 |2073|[Time Needed to Buy Tickets](https://leetcode.com/problems/time-needed-to-buy-tickets/)|[Java](../master/src/main/java/com/fishercoder/solutions/_2073.java) ||Easy||
 |2070|[Most Beautiful Item for Each Query](https://leetcode.com/problems/most-beautiful-item-for-each-query/)|[Java](../master/src/main/java/com/fishercoder/solutions/_2070.java) ||Medium||

src/main/java/com/fishercoder/solutions/_2075.java

@@ -0,0 +1,33 @@
+package com.fishercoder.solutions;
+
+public class _2075 {
+    public static class Solution1 {
+        public String decodeCiphertext(String encodedText, int rows) {
+            if (rows == 1) {
+                return encodedText;
+            }
+            int total = encodedText.length();
+            int cols = total / rows;
+            char[][] grid = new char[rows][cols];
+            int index = 0;
+            for (int i = 0; i < rows; i++) {
+                for (int j = 0; j < cols; j++) {
+                    grid[i][j] = encodedText.charAt(index++);
+                }
+            }
+            StringBuilder sb = new StringBuilder();
+            int colIndex = 0;
+            while (colIndex < cols) {
+                for (int j = colIndex, i = 0; j < cols && i < rows; j++, i++) {
+                    sb.append(grid[i][j]);
+                }
+                colIndex++;
+            }
+            int i = sb.length() - 1;
+            while (i >= 0 && sb.charAt(i) == ' ') {
+                i--;
+            }
+            return sb.substring(0, i + 1);
+        }
+    }
+}

src/test/java/com/fishercoder/_2075Test.java

@@ -0,0 +1,52 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._2075;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class _2075Test {
+    private static _2075.Solution1 solution1;
+    private static String encodedText;
+    private static int rows;
+    private static String expected;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _2075.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        encodedText = "ch   ie   pr";
+        rows = 3;
+        expected = "cipher";
+        assertEquals(expected, solution1.decodeCiphertext(encodedText, rows));
+    }
+
+    @Test
+    public void test2() {
+        encodedText = "iveo    eed   l te   olc";
+        rows = 4;
+        expected = "i love leetcode";
+        assertEquals(expected, solution1.decodeCiphertext(encodedText, rows));
+    }
+
+    @Test
+    public void test3() {
+        encodedText = "coding";
+        rows = 1;
+        expected = "coding";
+        assertEquals(expected, solution1.decodeCiphertext(encodedText, rows));
+    }
+
+    @Test
+    public void test4() {
+        encodedText = " b  ac";
+        rows = 2;
+        expected = " abc";
+        assertEquals(expected, solution1.decodeCiphertext(encodedText, rows));
+    }
+
+}