Range Addition

1. Mistake: we need to deduct operation[2] at position operation[1]+1, not operation[1]

public class Solution {
    public int[] getModifiedArray(int length, int[][] updates) {
        int[] arr = new int[length];
        if(updates.length == 0){
            return arr;
        }
        for (int[] operation : updates){
            arr[operation[0]] += operation[2];
            if (operation[1] + 1 < length)
                arr[operation[1]+1] -= operation[2];
        }
        int sum = 0;
        for (int i=0; i<arr.length; ++i){
            sum += arr[i];
            arr[i] = sum;
        }
        return arr;
    }
}