You have a bomb to defuse, and your time is running out! Your informer will provide you with a circular array code of length of n and a key k.
To decrypt the code, you must replace every number. All the numbers are replaced simultaneously.
k > 0, replace the ith number with the sum of the next k numbers.k < 0, replace the ith number with the sum of the previous k numbers.k == 0, replace the ith number with 0.As code is circular, the next element of code[n-1] is code[0], and the previous element of code[0] is code[n-1].
Given the circular array code and an integer key k, return the decrypted code to defuse the bomb!
Example 1:
Input: code = [5,7,1,4], k = 3 Output: [12,10,16,13] Explanation: Each number is replaced by the sum of the next 3 numbers. The decrypted code is [7+1+4, 1+4+5, 4+5+7, 5+7+1]. Notice that the numbers wrap around.
Example 2:
Input: code = [1,2,3,4], k = 0 Output: [0,0,0,0] Explanation: When k is zero, the numbers are replaced by 0.
Example 3:
Input: code = [2,4,9,3], k = -2 Output: [12,5,6,13] Explanation: The decrypted code is [3+9, 2+3, 4+2, 9+4]. Notice that the numbers wrap around again. If k is negative, the sum is of the previous numbers.
Constraints:
n == code.length1 <= n <= 1001 <= code[i] <= 100-(n - 1) <= k <= n - 1class Solution {
public int[] decrypt(int[] code, int k) {
int n = code.length, sum = 0;
int[] ans = new int[n];
if (k == 0)
return ans;
boolean isNegative = k < 0;
if (isNegative)
k = -k;
for (int i = 0; i < k; i++)
sum += code[i];
for (int i = k; i < n + k; i++) {
sum -= code[i - k];
sum += code[i % n];
if (isNegative)
ans[(i + 1) % n] = sum;
else
ans[i - k] = sum;
}
return ans;
}
}