solves defuse the bomb

Author: anishLearnsToCode

README.md

@@ -408,7 +408,7 @@
 | 1636 | [Sort Array by Increasing Frequency](https://leetcode.com/problems/sort-array-by-increasing-frequency)                                                    |                                                         [![Java](assets/java.png)](src/SortArrayByIncreasingFrequency.java)                                                          |                                                                                                                                   |
 | 1640 | [Check Array Formation Through Concatenation](https://leetcode.com/problems/check-array-formation-through-concatenation)                                  |                                                     [![Java](assets/java.png)](src/CheckArrayFormationThroughConcatenation.java)                                                     |                                                                                                                                   |
 | 1646 | [Get Maximum in Generated Array](https://leetcode.com/problems/get-maximum-in-generated-array)                                                            |                                                           [![Java](assets/java.png)](src/GetMaximumInGeneratedArray.java)                                                            |                                                                                                                                   |
-| 1652 | [Defuse the Bomb](https://leetcode.com/problems/defuse-the-bomb)                                                                                          |                                                                                                                                                                                      |                                                                                                                                   |
+| 1652 | [Defuse the Bomb](https://leetcode.com/problems/defuse-the-bomb)                                                                                          |                                                                  [![Java](assets/java.png)](src/DefuseTheBomb.java)                                                                  |                                                                                                                                   |
 | 1656 | [Design an Ordered Stream](https://leetcode.com/problems/design-an-ordered-stream)                                                                        |                                                                                                                                                                                      |                                                                                                                                   |
 | 1662 | [Check If Two String Arrays are Equivalent](https://leetcode.com/problems/check-if-two-string-arrays-are-equivalent)                                      |                                                                                                                                                                                      |                                                                                                                                   |
 | 1668 | [Maximum Repeating Substring](https://leetcode.com/problems/maximum-repeating-substring)                                                                  |                                                                                                                                                                                      |                                                                                                                                   |

src/DefuseTheBomb.java

@@ -0,0 +1,56 @@
+public class DefuseTheBomb {
+    public int[] decrypt(int[] code, int k) {
+        if (k == 0) return new int[code.length];
+        final Code codeData = new Code(code);
+        final int[] result = new int[code.length];
+        if (k > 0) {
+            for (int index = 0 ; index < result.length ; index++) {
+                result[index] = codeData.getSlice(index + 1, index + k);
+            }
+        } else {
+            for (int index = 0 ; index < result.length ; index++) {
+                result[index] = codeData.getSlice(index + k, index - 1);
+            }
+        }
+        return result;
+    }
+
+    private static final class Code {
+        private final int[] sum;
+        private final int codeSum;
+
+        Code(int[] code) {
+            this.sum = computeSum(code);
+            this.codeSum = sum[sum.length - 1];
+        }
+
+        private int[] computeSum(int[] array) {
+            final int[] sum = new int[array.length];
+            sum[0] = array[0];
+            for (int index = 1 ; index < array.length ; index++) {
+                sum[index] = sum[index - 1] + array[index];
+            }
+            return sum;
+        }
+
+        private int getIndex(int index) {
+            return (index + sum.length) % sum.length;
+        }
+
+        private int getSlice(int start, int end) {
+            final int startIndex = getIndex(start), endIndex = getIndex(end);
+            if (startIndex <= endIndex) {
+                return sum[endIndex] - (startIndex == 0 ? 0: sum[startIndex - 1]);
+            }
+            return codeSum - sum[startIndex - 1] + sum[endIndex];
+        }
+
+        private int[] getFullSumArray(int length) {
+            final int[] array = new int[length];
+            for (int index = 0 ; index < length ; index++) {
+                array[index] = codeSum;
+            }
+            return array;
+        }
+    }
+}