Java code efficiency: Look at the implementation of the method called intervalSums below. Design and implement a more efficient runtime algorithm for intervalSums. public static long intervalSums(int[] A, int[][] B) { long count = 0; for (int i = 0; i < A.length; i++) { for (int j = i; j < A.length; j++) { int sum = 0; for (int k = i; k i) B[j][i] = -1; // fill the lower "triangle" of B with -1s } } return count; }