I am new to permutations and combinations. I am provided with the number n and I can make a number with the help of n+1 digits which are 0,1,...n. I need to find in how many ways I can make the sum n by putting these n+1 digits in n places.

```
Like i am having number n=2
then
(a) 0 and 2 (b)1 and 1 (c)2 and 0 .
for a number n=3
then
(a)0,0,3 (b)0,3,0 (c)3,0,0 (d)0,1,2 (e)0,2,1 (f)1,0,2 (g)1,2,0 (h)2,0,1 (i)2,1,0 (j)1,1,1
So in total i have 10 ways to generate sum=3 by using the digits 0,1,2,3.
```

And also consider i can put these n+1 digits in n places only.

Answer:

The number of compositions of n into k nonnegative summands is (n+k-1) choose n by the stars-and-bars method. You have k=n, so the count is 2n-1 choose n. Your examples were 3C2=3 and 5C3=10.

java,math,set,linkedhashset

I am trying to do a homework in math which is find a subset of collection {1,2,..,n} where n is a number given in the code, I cannot get it done with the sublist so I need to get your help with a math programming. For example for n =...

algorithm,math,combinations

usually for lottery combinations the formula is "n! / (k!*(n-k)!)", e.g., for a 6/49 game it is "49!/(6!*(49-6)!)" is there a formula to calculate the same with m FIXED values (e.g., the numbers 1, 2, 3, and 4 are fixed) - 2 numbers are free for choice i thought the...

algorithm,math,infinite,clrs,gp

I am trying to prove an equation given in the CLRS exercise book. The equation is: Sigma k=0 to k=infinity (k-1)/2^k = 0 I solved the LHS but my answer is 1 whereas the RHS should be 0 Following is my solution: Let's say S = k/2^k = 1/2 +...

c,math,largenumber,integer-arithmetic

I've wrote an implementation of Murmur3 hash and have defined the 128-bit keys as hash128_t typedef struct { uint64_t p1; uint64_t p2; } hash128_t; I'm trying to write my own hashmap using these keys, but I'm not exactly sure how to do arithmetic with a struct nor a number this...

math,vector,3d,cube

I'm trying to figure out the math to find a random point inside a cube. I have something small but it can't take into account the rotation of the cube. Here are some images of my results. Here you can see the cube is rotated to some degree but when...

java,math,2d,map-projections,mercator

I'm trying to make a Java project that pinpoints the place on a image of a map, when given coordinates (taken from Google Maps). I've tried using the top-left corner of the image (place that has highest latitude, and the lowest longitude), as an some kind of an reference point,...

java,math

I did a code like this: public static double myPow(double x, int n){ if(n==0) return 1; double t = myPow(x, n/2); if(n % 2 != 0){ if(n < 0){ return (1 / t * t * x); } else { return t * t * x; } } else {...

java,arrays,random,combinations

I have to arrays with integers: int[] a={1,2,3,4,5}; int[] b={6,7}; I would like to generate an array, which contains pairs from the a and b arrays, in a random order, without duplicates. For example I would like to get the following result: c={(1,6),(2,7),(4,6),...} Thanks!...

c,algorithm,security,math,encryption

I'm trying to reverse the following code in order to provide a function which takes the buffer and decrypts it. void crypt_buffer(unsigned char *buffer, size_t size, char *key) { size_t i; int j; j = 0; for(i = 0; i < size; i++) { if(j >= KEY_SIZE) j = 0;...

arrays,matlab,loops,math,for-loop

I want to store mean_2....mean_8, std_2....std_8, and coVariance as separate columns in a file. Help Please? This Code calculates IntervalFeatures of Erp signal with 256 time frames and plots them Datapoints are store in A ___________HowTheCodeWorks________________________________________________ each 1x4 sliding sub-matrix is made a column for eg:- if A is...

c++,algorithm,math

Why does this function give the wrong answer -1 rather than the right answer 1 when I try this? myPow(-1.00000, -2147483648) double QuickPower(double x, int n) { if(n==0){ return 1; } if(n==1){ return x; } if(n>=2){ int res=n%2; double half=QuickPower(x,n/2); return res? Half*half*x: half*half; } } double myPow(double x, int...

javascript,arrays,math

i was playing around in code academy and for some reason when i change the last slaying i the else statement to true instead of making the person invincible it just crashes my browser any ideas why thank you in advance var slaying = true; var youHit = Math.floor(Math.random()*2); var...

algorithm,math,statistics,variance,standard-deviation

I'm successfully using Welford's method to compute running variance and standard deviation as described many times on Stack Overflow and John D Cook's excellent blog post. However in the stream of samples, sometimes I encounter a "rollback", or "remove sample" order, meaning that a previous sample is no longer valid...

python,math

I'm writing a python script to find out some things about randomization. I have the following code: from random import randint one = 0 two = 0 olddiff = 0 diff = 0 sumdiff = 0 avgdiff = 0 headcounter = 0 counter = 0 while (headcounter < 500000): while...

c++,math,geometry,angle

C++, I want calculate the angle of the direction of the two points. Here is a picture which shows the two points and the direction of how to get the angle of the direction? p1 - start point. p2 - direction point. me need direction angle(facing?) from p1 to p2...

python,combinations

I have a list of numbers and I wish to return a 2D list, preferably ordered from biggest to smallest (although I can do this afterwards), of all the possible combinations of multiplication (to yield the product of the original list) using all the elements of the list, without duplicates....

xml,xslt,math,operator-keyword,relational

I am newbie to XSLT. My am is to remove elements from XML based on a field if it is higher than some threshold value which I will be getting as parameter to it. My XML is as shown below: <tns:PM objectClass="MyNode" objectName="" className="com.project.converter.PMFamilyConverter" interfaceName="ComponentPM" xmlns:tns="http://www.myproject/SS/PMSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.myProject.com/SS/PM.xsd"> <tns:family desc="family0"...

linux,bash,math

I am new to Linux, and I just want a Bash Script to do basic arithmetic operation to a text file 1 2 3 4 and the results should be addition and multiplication in separate text files say add + 5 for 1st text file and mult * 5 in...

java,math,multiplication,string-length

Lets see if someone can wrap their head around this: if you get the length of a String using length(), the String always being multiples of 3,(in my case: "1.02.03.04.05.06.07.0 etc.") each 3 characters representing a letter, with .1 indicating a capitol letter, how do you use the length to...

math,big-o,time-complexity,asymptotic-complexity

I am doing this small task which I have to arrange asymptotic runtime in ascending order. Here are the runtimes: Here is the order I believe they should go in: log10(n^4), n^3, 2^((log4n)), 2^(100n), e^pi^4096, n! + 12^1000 Is this correct? Or are there any errors? Thanks!...

python,math,rounding

This question already has an answer here: How do you round UP a number in Python? 9 answers Python round up integer to next hundred 6 answers so i'm making a pizza program in Python 3.3 that takes input from the user and prints the amount of pizza's needed....

matlab,math

The follow plot shows my question: I would like to add a line between the points of 1e-1 and 1e-2. So I thought just (1e-1+1e-2)/2. But for a log scale that is not "midway". How can I calculate the "visual" midway value between these, or any two points in this...

math,fpga,cordic

I'm studying the cordic. And I found the cordic gain. K=0.607XXX. From CORDIC, K_i = cos(tan^-1(2^i)). As I know the K is approched 0.607xxx.when I is going to infinity this value come up with from all K multiplying. I understand the reason of exist each k. But I am curioused...

algorithm,math,time-complexity,computer-science,recurrence-relation

I need to solve the exact time complexity for the brute force version of the Traveling Salesman using a recurrence relation. I've worked out the recurrence relation to be as follows: T(n)=T(n-1)*(n-1)+1 But I'm having trouble reducing that that to a closed form of the function, and thus get the...

c++,loops,math

I have to solve problem using c++, and can't really come up with solution. The condition is. In a skyscraper there are a lot of offices, on every office door there must be put plate with its number from 1 to the number of the last office. The plate can...

c++,math,rotation,grid,geometry

If i had an array of point structs defined as struct Point{ float x; float y; }; How would I rotate the points in this array by a given angle? As an example: Any help would be appreciated!...

algorithm,math,greatest-common-divisor,number-theory,clrs

This is the pseudo code for calculating integer factorisation took from CLRS. But what is the point in calculating GCD involved in Line 8 and the need for doubling k when i == k in Line 13.? Help please....

javascript,math,svg

I'm trying to make my robot follow a path that is a drawn SVG path on a webpage. To keep it simple, assume that the SVG Is like so: <svg xmlns="http://www.w3.org/2000/svg"> <path id="path" d="M 100 100 L 300 300 L 100 500 z"> </svg> Which makes a triangle. The robot...

math,floating-point,fixed-point

I need to multiply X with a floating point number in floating point as i don't have floating point operations in my processor. I understand the method but don't know why that method exists? Suppose we want to multiply 2*4.5 in decimal I do the below: 2 * 4.5 (100.1)...

math,cordic

How can we use cordic to tanh(x+1)/tanh(x) I can't get a idea about how to apply cordic to above function. In other word, which point on the above function, can we apply cordic?...

math,unity3d,numbers

I'm working on a project where I have a pane that goes from 0 to 500 on the x and z, but I need to convert that coordinate (from 0 to 500) to a float in the range of 0.0 to 1.0 in because it is required from some of...

javascript,excel,math

In my javascript code I have the following Math.log(20) = 2.995732273553991 In my excel formula I try to replicate this with =LOG(20) = 1.301029996 Anyone have any idea why I'm getting two different outcomes? I'd like my excel to match my js. ...

c++,algorithm,math,recursion

I'm trying to find all possible solutions to the 3X3 magic square. There should be exactly 8 solutions. My code gets them all but there are a lot of repeats. I'm having a hard time tracking the recursive steps to see why I'm getting all the repeats. // This program...

python,math

Need help with this of python Write a program with 3 functions to find out the (function 1) dot product, (function 2) angle, and (function 3) cross product of two vectors. Program should ask a user to input three points in 3D space such as (x1, y1, z1), (x2, y2,...

javascript,math,chartjs

I use Chart.js (http://www.chartjs.org) to show traffic usage for different units using Bar Chart. If I have big range of usage (1 unit 2.5GB, 2 unit 2.5MB, 3 unit 2.5kB, 4 unit 0B) smallest values are not available (I cannot hover over or click on them) when bring them to...

arrays,matlab,math,for-loop,while-loop

This is my one dimensional array A, containing 10 numbers: A = [-8.92100000000000 10.6100000000000 1.33300000000000 ... -2.57400000000000 -4.52700000000000 9.63300000000000 ... 4.26200000000000 16.9580000000000 8.16900000000000 4.75100000000000]; I want the loop to go through like this; (calculating mean interval wise) - Interval length of 2,4,8 (a(1)+a(2))/2 - value stored in one block of...

math,vhdl,fpga,rtl,cordic

From CORDIC, K_i = cos(tan^-1(2^i)). As I know the K is approached 0.607xxx. How do I approach to 0.607xxx? Also does it mean that I can use 0.607xxx instead of cos(tan^-1(2^I))? I am citing from this article. I am trying to implement hyperbolic tanh function. And so far I understand...

string,algorithm,python-2.7,math

I have a problem where I am trying to prevent repeats of a string. So far the best solution is to compare the strings for a percentage and check if it is above a certain fixed point. I've looked up Levenshtein distance but so far I believe it does not...

c++,math,rotation,rotational-matrices,separating-axis-theorem

The problem is in Polygon::FindAxisLeastPenetration: double Polygon::FindAxisLeastPenetration(unsigned int *faceIndex, const Polygon &polygonA, const Polygon &polygonB) const { double bestDistance = -std::numeric_limits<double>::infinity(); unsigned int bestIndex; for (unsigned int i = 0; i < polygonA.points.size(); i++) { Vector2D n = polygonA.normals[i]; Vector2D nw = polygonA.rotationMatrix * n; //ROTATION Matrix22 buT = polygonB.rotationMatrix.Transposed();...

c,algorithm,math,recursion

I am not sure if power by squaring takes care of negative exponent. I implemented the following code which works for only positive numbers. #include <stdio.h> int powe(int x, int exp) { if (x == 0) return 1; if (x == 1) return x; if (x&1) return powe(x*x, exp/2); else...

python,algorithm,sorting,math

I am looking for a basic algorithm that gives more weigh to the recent reviews. So, the output value of the algorithm is mutable. For example, two reviews with exactly the same score, will have a different ranking based on the timestamp of the creation. Review_1 Score 10 creation 10/5/2014...

javascript,math,percentage

var current = 12000; var june = 14600; var may = 11200; I want percent change with respect to 'current' month parameter. The output should be in percent and it can add or subtract w.r.t. the current month. How to do this?...

math,lua,love2d

So I've been working at this on and off for a week, googling and all and I haven't found how to do this. I have a table of "rays" and a table of "lines", and I want the lines to act as mirrors and reflect a ray whenever the ray...

php,math,hash

I'm generating a somewhat unique code that I don't want to repeat within at least 1000 consecutive numbers this is my function. take a number multiply it by another number then take the last $length=5 digits before the decimal point function createPseudoUniqueString($input,$length) { return substr( intval($input*738510.93067),-$length) ; } is there...

math,javafx,geometry,coordinates

I have a line which has points (x1,y1) and (x2,y2). I wanted to attach a Button to it, it should align with the line by rotating based on the line segment points. I need some help in calculating the rotation angle for the Button.

html,math

Is it possible to perform math operations within HTML, like <div width="50/2">? Or can this only be done using Javascript or CSS?

php,mysql,math,phpmyadmin

I am trying to math between value of 0 but in php code it's work properly but when that value come from database then it does not work. Here is a demo to test only PHP code: <?php $a = 0; echo $a+1; ?> The result of this code 1...

python,math,combinations,itertools

Other than doing this: from itertools import combinations def brute_force(x): for l in range (1,len(x)+1): for f in list(combinations(range(0,len(x)),l)): yield f x = range(1,18) len(list(brute_force(x))) [out]: 131071 How could I mathematically calculate the number of all possible combinations? Is there a way to do it computationally without enumerating the possible...