exercise_2.js

function memoize(func) {
  var memo = {};
  var slice = Array.prototype.slice;
  return function () {
    var args = slice.call(arguments);
    if (args in memo) return memo[args];
    else return (memo[args] = func.apply(this, args));
  };
}

function sumArray(arr) {
  let sum = 0;
  for (let entry of arr) {
    sum = sum + entry;
  }
  return sum;
}

function minArray(arr) {
  let min = arr[0];
  for (let entry of arr) {
    if (entry < arr[0]) min = entry;
  }
  return min;
}

function calculatePower(l, r) {
  const slicedPower = myPower.slice(l, r + 1);
  const min = minArray(slicedPower);
  const sum = sumArray(slicedPower);
  return min * sum;
}

const memoizedCalculatePower = memoize(calculatePower);
var myPower;

function findTotalPower(power) {
  myPower = power;
  let totalSum = 0n;
  for (let l = 0; l < myPower.length; l++) {
    for (let r = l; r < myPower.length; r++) {
      const powerResult = memoizedCalculatePower(l, r);
      totalSum = totalSum + BigInt(powerResult);
    }
  }
  return (totalSum % 1000000007n).toString();
}