A function to calculate estimated duration - excel-formula

I would like to know if there is an existing function in Excel (e.g., in finance) to undertake the following task.
Imagine we have planned the sales of a product for 2013 as C5:G6. And we have stock in J10. We want to calculate the estimated number of months the stock can support the sales. For instance, given the stock is 360, it has enough quantity for 100 in January and 200 in February, and there will be 60 left, which will be consumed in 60/300 months, thus the expected return value is 2,2 months.
I have written a long formula in Excel to do so:
= LET(
ps;
C6:G6;
sq;
J10;
cumuls;
SCAN(0; ps; LAMBDA(a; b; a + b));
m;
REDUCE(
0;
cumuls;
LAMBDA(acc; value; IF(value <= sq; acc + 1; acc)));
IFS(
m = 0;
sq / INDEX(ps; 1; 1);
m >= COLUMNS(ps);
m;
TRUE;
(sq - INDEX(cumuls; 1; m)) / INDEX(ps; 1; m + 1) + m))
However, I'm wondering if there is any existing function in Excel for this purpose.

Not sure if this is what you're after, but this formula would spill the result in one go:
=LET(months,TRANSPOSE(C6:G6),
stock,J6:J11,
cml,SCAN(0,months,LAMBDA(a,b,a+b)),
mx,XMATCH(stock,cml,1),
(stock-INDEX(cml,mx))/INDEX(months,mx)+mx)

Related

(DP) Memoization - How to know if it starts from the top or bottom?

It hasn't been long since I started studying algorithm coding tests, and I found it difficult to find regularity in Memoization.
Here are two problems.
Min Cost Climbing Stairs
You are given an integer array cost where cost[i] is the cost of ith step on a staircase. Once you pay the cost, you can either climb one or two steps.
You can either start from the step with index 0, or the step with index 1.
Return the minimum cost to reach the top of the floor.
Min Cost Climbing Stairs
Recurrence Relation Formula:
minimumCost(i) = min(cost[i - 1] + minimumCost(i - 1), cost[i - 2] + minimumCost(i - 2))
House Robber
You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from robbing each of them is that adjacent houses have security systems connected and it will automatically contact the police if two adjacent houses were broken into on the same night.
Given an integer array nums representing the amount of money of each house, return the maximum amount of money you can rob tonight without alerting the police.
House Robber
Recurrence Relation Formula:
robFrom(i) = max(robFrom(i + 1), robFrom(i + 2) + nums(i))
So as you can see, first problem consist of the previous, and second problem consist of the next.
Because of this, when I try to make recursion function, start numbers are different.
Start from n
int rec(int n, vector<int>& cost)
{
if(memo[n] == -1)
{
if(n <= 1)
{
memo[n] = 0;
} else
{
memo[n] = min(rec(n-1, cost) + cost[n-1], rec(n-2, cost) + cost[n-2]);
}
}
return memo[n];
}
int minCostClimbingStairs(vector<int>& cost) {
const int n = cost.size();
memo.assign(n+1,-1);
return rec(n, cost); // Start from n
}
Start from 0
int getrob(int n, vector<int>& nums)
{
if(how_much[n] == -1)
{
if(n >= nums.size())
{
return 0;
} else {
how_much[n] = max(getrob(n + 1, nums), getrob(n + 2, nums) + nums[n]);
}
}
return how_much[n];
}
int rob(vector<int>& nums) {
how_much.assign(nums.size() + 2, -1);
return getrob(0, nums); // Start from 0
}
How can I easily know which one need to be started from 0 or n? Is there some regularity?
Or should I just solve a lot of problems and increase my sense?
Your question is right, but somehow examples are not correct. Both the problems you shared can be done in both ways : 1. starting from top & 2. starting from bottom.
For example: Min Cost Climbing Stairs : solution that starts from 0.
int[] dp;
public int minCostClimbingStairs(int[] cost) {
int n = cost.length;
dp = new int[n];
for(int i=0; i<n; i++) {
dp[i] = -1;
}
rec(0, cost);
return Math.min(dp[0], dp[1]);
}
int rec(int in, int[] cost) {
if(in >= cost.length) {
return 0;
} else {
if(dp[in] == -1) {
dp[in] = cost[in] + Math.min(rec(in+1, cost), rec(in+2, cost));
}
return dp[in];
}
}
However, there are certain set of problems where this is not easy. Their structure is such that if you start in reverse, the computation could get complicated or mess up the future results:
Example: Reaching a target sum from numbers in an array using an index at max only 1 time. Reaching 10 in {3, 4, 6, 5, 2} : {4,6} is one answer but not {6, 2, 2} as you are using index (4) 2 times.
This can be done easily in top down way:
int m[M+10];
for(i=0; i<M+10; i++) m[i]=0;
m[0]=1;
for(i=0; i<n; i++)
for(j=M; j>=a[i]; j--)
m[j] |= m[j-a[i]];
If you try to implement in bottom up way, you will end up using a[i] multiple times. You can definitely do it bottom up way if you figure a out a way to tackle this messing up of states. Like using a queue to only store reached state in previous iterations and not use numbers reached in current iterations. Or even check if you keep a count in m[j] instead of just 1 and only use numbers where count is less than that of current iteration count. I think same thing should be valid for all DP.

An internal unit of company XYZ provides services to other departments

Example 1:
``
Given S="300.01" and B-["300.00", "200.00*,*100.00"].
R[0]="150.00" (=300.01 300.00/600.00) R[1]="100.00" (=150.01* 200.00/300.00)
R[2]="50.01" (=50.01*100.00/100.00)
Example 2 (Pay careful attention to this one).
Given S="1.00" and B=["0.05","1.00"]. 1. First we consider 1.00 because it is the largest,
a. 1.00*1.00/1.05~0.95238...
b. Round 0.95238... to "0.95". Rounding down to carry pennies to smaller departments. c. Set R[1]=0.95. Notice, this is in the same place as 1.00. It is the 2nd value in the result! 2. Now we have 0.05 left
Next we look at the smaller B[0]=0.05 department
a. 0.05 0.05/0.05 = 0.05 b. No rounding required
c. Set R[0]=0.05. R=["0.05", "0.95"]
`
Write a function:
class Solution { public String[] solution(String 5, String[] B); }
that, given a string S representing the total excess billables and an array B consisting of K strings representing the undiscounted bills for each customer. The return value should be an array of strings R (length M) in the same order as B representing the amount of the discount to each customer.
Notes:
The total S should be completely refunded. Neither more nor less than S should be
returned. Don't lose or gain a penny!
Be careful with the types you choose to represent currencies. Floating points numbers are notoriously error prone for precise calculations with currencies.
Test Output
Amounts should be rounded down to the nearest $0.01. By design, fractional pennies are pushed to groups with smaller unadjusted invoices.
Results should be represented with 2 decimal places of precision as strings, even if these are both zeroes. ex. "100.00" 5. You may assume sensible inputs. The total to be discounted will never exceed the total of the
unadjusted invoices.
Please do pay attention to returning the discounts in the same order as the incoming invoices.
Answer:::
def solution(A):
answer = 0
current_sum = 0
#Currently there is one empty subarray with sum 0
prefixSumCount = {0:1}
for list_element in A:
current_sum = current_sum + list_element
if current_sum in prefixSumCount:
answer = answer + prefixSumCount[current_sum]
if current_sum not in prefixSumCount:
prefixSumCount[current_sum] = 1
else:
prefixSumCount[current_sum] = prefixSumCount[current_sum] + 1
if answer > 1000000000:
return -1
else:
return answer
#Sample run
A = [2,-2,3,0,4,-7]
print(solution(A))
strong text
Find my solution for JavaScript
You can avoid function sumArray and use the sum funciton with reducer within solution function.
enter code here
function solution(S, B) {
// write your code in JavaScript (Node.js 8.9.4)
let copyArray=[...B];
let solutionObj={};
//ordered array to consider last first
copyArray.sort();
//calculating sum of values within array
let sumArray=B.reduce((acc,value)=> acc+Number(value),0);
//calculating values of array
//loop for ading on to solvin array
let initial=S;
for(i=copyArray.length-1;i>=0;i--){
//obtaining index of value addded to solution array
let index=B.indexOf(copyArray[i]);
let value=initial*copyArray[i]/sumArray;
value=i==0?Math.ceil(value*100)/100:Math.floor(value*100)/100;
solutionObj[index]=value.toFixed(2);
}
return Object.values(solutionObj) ;
}
console.log(solution(300.01,["300.00","200.00","100.00"]))
console.log(solution(1.00,["0.05","1.00"]))
These are the resulting entries
Solution in java for the same coding exercise
public String[] solution(String S, String[] B) {
List<Double> list = Arrays.stream(B).sorted(Comparator.comparingDouble(v->Double.valueOf((String) v)).reversed()).map(Double::parseDouble).collect(Collectors.toList());
Double S1 = Double.valueOf(S);
String R[] = new String[B.length];
Double total = 0.00;
for (int i = 0; i< list.size(); i++){
Double individualValue = list.get(i);
Double sumTotal = 0.0;
for(int j = i+1;j < list.size(); j++){
sumTotal+=list.get(j);
}
BigDecimal data = new BigDecimal(S1 * (individualValue / (individualValue + sumTotal)));
data = data.setScale(2, RoundingMode.FLOOR);
total+=data.doubleValue();
R[i] = String.valueOf(data);
S1 = S1 - Double.valueOf(R[i]);
}
Double diff = new BigDecimal(Double.valueOf(S) - total).setScale(2, RoundingMode.HALF_DOWN).doubleValue();
if (diff > 0) {
R[B.length - 1] = String.valueOf(Double.valueOf(R[B.length - 1]) + diff);
}
return R;
}

Fuzzy logic on price calculation

I am having one price calculation code in C#.There is particular sequence of calculating all the prices and taxes.how to apply fuzzy logic so that I will get related search of that particular price.That means if one of tax name is 'cost/kg'.So I should get all the names of taxes or prices which start from C or CO.
A simple way would be getting prices within some min/max bounds of what has been searched
double k = 0.1;
double min = searchedAmount - (searchedAmount * k);
double max = searchedAmount + (searchedAmount * k);
var results = products.Where(p => p.Price >= min && p.Price <= max);

Finding the local maxima/peaks and minima/valleys of histograms

Ok, so I have a histogram (represented by an array of ints), and I'm looking for the best way to find local maxima and minima. Each histogram should have 3 peaks, one of them (the first one) probably much higher than the others.
I want to do several things:
Find the first "valley" following the first peak (in order to get rid of the first peak altogether in the picture)
Find the optimum "valley" value in between the remaining two peaks to separate the picture
I already know how to do step 2 by implementing a variant of Otsu.
But I'm struggling with step 1
In case the valley in between the two remaining peaks is not low enough, I'd like to give a warning.
Also, the image is quite clean with little noise to account for
What would be the brute-force algorithms to do steps 1 and 3? I could find a way to implement Otsu, but the brute-force is escaping me, math-wise. As it turns out, there is more documentation on doing methods like otsu, and less on simply finding peaks and valleys. I am not looking for anything more than whatever gets the job done (i.e. it's a temporary solution, just has to be implementable in a reasonable timeframe, until I can spend more time on it)
I am doing all this in c#
Any help on which steps to take would be appreciated!
Thank you so much!
EDIT: some more data:
most histogram are likely to be like the first one, with the first peak representing background.
Use peakiness-test. It's a method to find all the possible peak between two local minima, and measure the peakiness based on a formula. If the peakiness higher than a threshold, the peak is accepted.
Source: UCF CV CAP5415 lecture 9 slides
Below is my code:
public static List<int> PeakinessTest(int[] histogram, double peakinessThres)
{
int j=0;
List<int> valleys = new List<int> ();
//The start of the valley
int vA = histogram[j];
int P = vA;
//The end of the valley
int vB = 0;
//The width of the valley, default width is 1
int W = 1;
//The sum of the pixels between vA and vB
int N = 0;
//The measure of the peaks peakiness
double peakiness=0.0;
int peak=0;
bool l = false;
try
{
while (j < 254)
{
l = false;
vA = histogram[j];
P = vA;
W = 1;
N = vA;
int i = j + 1;
//To find the peak
while (P < histogram[i])
{
P = histogram[i];
W++;
N += histogram[i];
i++;
}
//To find the border of the valley other side
peak = i - 1;
vB = histogram[i];
N += histogram[i];
i++;
W++;
l = true;
while (vB >= histogram[i])
{
vB = histogram[i];
W++;
N += histogram[i];
i++;
}
//Calculate peakiness
peakiness = (1 - (double)((vA + vB) / (2.0 * P))) * (1 - ((double)N / (double)(W * P)));
if (peakiness > peakinessThres & !valleys.Contains(j))
{
//peaks.Add(peak);
valleys.Add(j);
valleys.Add(i - 1);
}
j = i - 1;
}
}
catch (Exception)
{
if (l)
{
vB = histogram[255];
peakiness = (1 - (double)((vA + vB) / (2.0 * P))) * (1 - ((double)N / (double)(W * P)));
if (peakiness > peakinessThres)
valleys.Add(255);
//peaks.Add(255);
return valleys;
}
}
//if(!valleys.Contains(255))
// valleys.Add(255);
return valleys;
}

AS2: How to iterate X times through a percentage calculation (containing a circular reference)?

Here is a question for the Excel / math-wizards.
I'm having trouble doing a calculation which is based on a formula with a circular reference. The calculation has been done in an Excel worksheet.
I've deducted the following equations from an Excel file:
a = 240000
b = 1400 + c + 850 + 2995
c = CEIL( ( a + b ) * 0.015, 100 )
After the iterations the total of A+B is supposed to be 249045 (where b = 9045).
In the Excel file this gives a circular reference, which is set to be allowed to iterate 4 times.
My problem: Recreate the calculation in AS2, going through 4 iterations.
I am not good enough at math to break this problem down.
Can anyone out there help me?
Edit: I've changed the formatting of the number in variable a. Sorry, I'm from DK and we use period as a thousand separator. I've removed it to avoid confusion :-)
2nd edit: The third equation, C uses Excels CEIL() function to round the number to nearest hundredth.
I don't know action script, but I think you want:
a = 240000
c = 0
for (i = 0; i < 4; i++){
b = 1400 + c + 850 + 2995
c = (a + b) * 0.015
}
But you need to determine what to use for the initial value of c. I assume that Excel uses 0, since I get the same value when running the above as I get in Excel with iterations = 4, c = 3734.69...
Where do you get the "A + B is supposed to be 249045" value? In Excel and in the above AS, b only reaches 8979 with those values.
function calcRegistrationTax( amount, iterations ) {
function roundToWhole( n, to ) {
if( n > 0 )
return Math.ceil( n/ to ) * to;
else if( n < 0)
return Math.floor( n/ to ) * to;
else
return to;
}
var a = amount;
var b = 0;
var c = 0
for (var i = 0; i < iterations; i++){
b = basicCost + ( c ) + financeDeclaration + handlingFee;
c = ( a + b ) * basicFeeRatio;
c = roundToWhole( c, 100 );
}
return b;
}
totalAmount = 240000 + calcRegistrationTax( 240000, 4 ); // This gives 249045
This did it, thanks to Benjamin for the help.

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