LeetCode-in-Java
1073. Adding Two Negabinary Numbers
Medium
Given two numbers arr1 and arr2 in base -2, return the result of adding them together.
Each number is given in array format: as an array of 0s and 1s, from most significant bit to least significant bit. For example, arr = [1,1,0,1] represents the number (-2)^3 + (-2)^2 + (-2)^0 = -3. A number arr in array, format is also guaranteed to have no leading zeros: either arr == [0] or arr[0] == 1.
Return the result of adding arr1 and arr2 in the same format: as an array of 0s and 1s with no leading zeros.
Example 1:
Input: arr1 = [1,1,1,1,1], arr2 = [1,0,1]
Output: [1,0,0,0,0]
Explanation: arr1 represents 11, arr2 represents 5, the output represents 16.
Example 2:
Input: arr1 = [0], arr2 = [0]
Output: [0]
Example 3:
Input: arr1 = [0], arr2 = [1]
Output: [1]
Constraints:
1 <= arr1.length, arr2.length <= 1000arr1[i]andarr2[i]are0or1arr1andarr2have no leading zeros
Solution
public class Solution {
public int[] addNegabinary(int[] arr1, int[] arr2) {
int len1 = arr1.length;
int len2 = arr2.length;
int[] reverseArr1 = new int[len1];
for (int i = len1 - 1; i >= 0; i--) {
reverseArr1[len1 - i - 1] = arr1[i];
}
int[] reverseArr2 = new int[len2];
for (int i = len2 - 1; i >= 0; i--) {
reverseArr2[len2 - i - 1] = arr2[i];
}
int[] sumArray = new int[Math.max(len1, len2) + 2];
System.arraycopy(reverseArr1, 0, sumArray, 0, len1);
for (int i = 0; i < sumArray.length; i++) {
if (i < len2) {
sumArray[i] += reverseArr2[i];
}
if (sumArray[i] > 1) {
sumArray[i] -= 2;
sumArray[i + 1]--;
} else if (sumArray[i] == -1) {
sumArray[i] = 1;
sumArray[i + 1]++;
}
}
int resultLen = sumArray.length;
for (int i = sumArray.length - 1; i >= 0; i--) {
if (sumArray[i] == 0) {
resultLen--;
} else {
break;
}
}
if (resultLen == 0) {
return new int[] {0};
}
int[] result = new int[resultLen];
for (int i = resultLen - 1; i >= 0; i--) {
result[resultLen - i - 1] = sumArray[i];
}
return result;
}
}