2.4.35 Sampling from a discrete probability distribution. Write a class Sample with a constructor that takes an array p[] of double values as argument and supports the following two operations: random() return an index i with probability p[i]/T (where T is the sum of the numbers in p[])and change(i, v)change the value of p[i] to v. Hint: Use a complete binary tree where each node has implied weight p[i]. Store in each node the cumulative weight of all the nodes in its subtree. To generate a random- index, pick a random number between 0 and T and use the cumulative weights to determine which branch of the subtree to explore. When updating p[i], change all of the weights of the nodes on the path from the root to i. Avoid explicit pointers, as we do for heaps.