1652. Defuse the bomb

//1652. Defuse the bomb

class Solution {
    public int[] decrypt(int[] code, int k) {
        int n = code.length;     
        int ans[] = new int[n];
        int start = 0, end = 0; 

        if(k == 0) {
            return ans;
        }

        if(k > 0) {
            start = 1;
            end = k ; 
        }
        else {
            start = n - Math.abs(k);
            end = n - 1;
        }

        int sum = 0; 
        
        for(int i = start; i <= end; i++) {
            sum += code[i];
        }

        for(int i = 0; i < n; i++) {
            ans[i] = sum ; 
            sum = sum - code[(start) % n];
            sum = sum + code[(end + 1) % n]; 
            start++; 
            end++;  
        }
        
        return ans;
    }
}