Same idea in java. Thank you for posting this by the way , helped immensely!

static long arrayManipulation(int n, int[][] queries) {
    long[] diff = new long[n+2];
    for(int[] query : queries){
        diff[query[0]]+=query[2]; //a,b,k
        diff[query[1]+1]-=query[2];
    }
    long  max =0;
    long current=0; 
    for(long i : diff){
        current+=i;
        if (current >  max )
            max = current;
    }
    return max;
}