Add Pascal's Triangle (#2871)

Co-authored-by: Andrii Siriak <siryaka@gmail.com>
This commit is contained in:
Hardik Soni
2021-12-14 01:34:19 +05:30
committed by GitHub
parent 734f7a4a04
commit b1242e045b
3 changed files with 112 additions and 5 deletions

View File

@ -0,0 +1,65 @@
package com.thealgorithms.maths;
import java.util.Scanner;
public class PascalTriangle {
/**
*In mathematics, Pascal's triangle is a triangular array of the binomial coefficients that arises
* in probability theory, combinatorics, and algebra. In much of the Western world, it is named after
* the French mathematician Blaise Pascal, although other mathematicians studied it centuries before
* him in India, Persia, China, Germany, and Italy.
*
* The rows of Pascal's triangle are conventionally enumerated starting with row n=0 at the top (the 0th row).
* The entries in each row are numbered from the left beginning with k=0 and are usually staggered relative
* to the numbers in the adjacent rows. The triangle may be constructed in the following manner:
* In row 0 (the topmost row), there is a unique nonzero entry 1. Each entry of each subsequent row is
* constructed by adding the number above and to the left with the number above and to the right, treating
* blank entries as 0. For example, the initial number in the first (or any other) row is 1 (the sum of 0 and 1),
* whereas the numbers 1 and 3 in the third row are added to produce the number 4 in the fourth row. *
*
*<p>
* link:-https://en.wikipedia.org/wiki/Pascal%27s_triangle
*
* <p>
* Example:-
* 1
* 1 1
* 1 2 1
* 1 3 3 1
* 1 4 6 4 1
* 1 5 10 10 5 1
* 1 6 15 20 15 6 1
* 1 7 21 35 35 21 7 1
* 1 8 28 56 70 56 28 8 1
*
*/
public static int[][] pascal(int n)
{
/**
* @param arr An auxiliary array to store generated pascal triangle values
* @return
*/
int[][] arr = new int[n][n];
/**
* @param line Iterate through every line and print integer(s) in it
* @param i Represents the column number of the element we are currently on
*/
for (int line = 0; line < n; line++)
{
/**
* @Every line has number of integers equal to line number
*/
for (int i = 0; i <= line; i++)
{
// First and last values in every row are 1
if (line == i || i == 0)
arr[line][i] = 1;
// The rest elements are sum of values just above and left of above
else
arr[line][i] = arr[line-1][i-1] + arr[line-1][i];
}
}
return arr;
}
}