Prefix Sum presented by Easy LeetCode

function getPrefixSums(values: readonly number[]): number[];
function getPrefixSums<T>(
  elements: readonly T[],
  getElementValue: (element: T) => number
): number[];
function getPrefixSums(
  elements: readonly any[],
  getElementValue?: (element: any) => number
): number[] {
  const prefixSums = new Array(elements.length);

  if (typeof getElementValue === "undefined") {
    getElementValue = (element) => element;
  }

  prefixSums[0] = getElementValue(elements[0]);

  for (let i = 1; i < elements.length; i++) {
    prefixSums[i] = prefixSums[i - 1] + getElementValue(elements[i]);
  }

  return prefixSums;
}

Use Prefix Sum on LeetCode

Copy this snippet and paste it to the bottom of your LeetCode editor so that you can use the Prefix Sum.

Don’t use it where the problem itself is to implement a Prefix Sum.