Running Sum of 1d Array

Given an array nums We defined a running sum of an array as runningSum[i] = sum(nums[0]…nums[i]).

Return the running sum of nums.

My solution:

/**
 * Overwritten Input Approach
 *
 * @param {number[]} nums
 * @return {number[]}
 */
const runningSum = function (nums) {
  for (let i = 1; i < nums.length; i++) {
    nums[i] += nums[i - 1];
  }
  return nums;
};
  • Time Complexity: O(n)
  • Space Complexity: O(1)

Richest Customer Wealth

You are given an m x n integer grid accounts where accounts[i][j] is the amount of money the i​​​​​​​​​​​th​​​​ customer has in the j​​​​​​​​​​​th​​​​ bank. Return the wealth that the richest customer has.

A customer’s wealth is the amount of money they have in all their bank accounts. The richest customer is the customer that has the maximum wealth.

My solution:

/**
 * Find wealthiest account.
 *
 * @param {number[][]} accounts
 * @return {number}
 */
const maximumWealth = function (accounts) {
  let max = 0;
  accounts.forEach((account) => {
    const sum = account.reduce((prev, curr) => prev + curr, 0);
    if (sum > max) {
      max = sum;
    }
  });
  return max;
};