I am looking for a Pascals triangle using python script
I have done till here and have no idea how to add on
numstr= raw_input("please enter the height:")
height = int( )
tri = []
row1 = [1]
row2 = [1, 1]
tri.append(row1)
tri.append(row2)
while len(tri) < height:
You would have to take the last row there is in the triangle and create the next one like this:
You could also calculate the new numbers using binomial coefficients, though that's likely a little more work to get right.
Actually, the next row is crossed axis sum of last row. For example, if the last row is [1, 1], the next row would be:
[1, 1]
+ [1, 1]
-----------
= [1, 2, 1]
[1, 2, 1]
+ [1, 2, 1]
--------------
= [1, 3, 3, 1]
So, the loop body can be like this:
tri.append(map(lambda x, y: x + y, [0] + tri[-1], tri[-1] + [0]))
try the scipy pascal module:
from scipy.linalg import pascal
pascal(6, kind='lower')
output:
array([[ 1, 0, 0, 0, 0, 0],
[ 1, 1, 0, 0, 0, 0],
[ 1, 2, 1, 0, 0, 0],
[ 1, 3, 3, 1, 0, 0],
[ 1, 4, 6, 4, 1, 0],
[ 1, 5, 10, 10, 5, 1]], dtype=uint64)
here is my solution to generate a pascal triangle
def factorial(x):
return 1 if x == 0 else x * factorial(x - 1)
def triangle(n):
return [[factorial(i) / (factorial(j) * factorial(i - j)) for j in range(i + 1)] for i in range(n)]
This is python code for Pascal's triangle:
# python code for Pascal's Triangle
# printPascal() function for printing pascal's triangle.
def printPascal(N):
# declaring 2 array
arr = [1]
temp = []
print("pascal's triangle of", N, "Rows...")
# calculating next rows.
for i in range(N):
# printing current row.
print("rows", i+1, end=" : ")
for j in range(len(arr)):
print(arr[j], end=' ')
print()
# calculating next rows.
temp.append(1)
for j in range(len(arr)-1):
temp.append(arr[j] + arr[j + 1])
temp.append(1)
# copy next row to current row.
arr = temp
# initialize temp to empty array.
temp = []
# Driver code
N = 9
printPascal(N)
For more details:https://algorithmdotcpp.blogspot.com/2021/07/print-n-rows-of-pascals-triangle-in-cpp-and-python.html
// C++ code for pascal triangle
#include<stdio.h>
#include<ctype.h>
#include<conio.h>
#include<time.h>
#include<stdlib.h>
long unsigned int Factorial(long unsigned int Number)
{
long unsigned int Fact=0;
if (Number==0)
return (long unsigned int) 1;
else
{ Fact=Number*Factorial(Number-1);
return Fact;
}
}
long unsigned int Combination(long unsigned int num1,long unsigned int num2)
{
long unsigned int Comb,num3;
long unsigned int Factor1, Factor2,Factor3;
Factor1=Factorial(num1);
Factor2=Factorial(num2);
num3=num1-num2;
Factor3=Factorial(num3);
Comb=Factor1/(Factor2*Factor3);
return(Comb);
}
int main()
{
long unsigned int i,j,Num=0;
long unsigned int **Matrix;
clrscr();
printf(" %d\n " ,sizeof(long unsigned int));
printf("Enter Index of Square Matrix Num =: ");
scanf ("%lu",&Num);
Matrix=(long unsigned int **) malloc(Num*Num*sizeof(long unsigned int *));
for( i=0;i<Num;i++)
{ for (j=0;j<Num;j++)
{ *(*(Matrix+i)+j)=0;
}
}
for(i=0;i<Num;i++)
{ for(j=0;j<=i;j++)
{ printf(" %lu " , *(*(Matrix+i)+j)); }
printf("\n");
}
for(i=0;i<Num;i=i+1)
{
for(j=0;j<=i;j=j+1)
{
*(*(Matrix+i)+j)=Combination(i,j);
}
printf("\n");
}
for(i=0;i<Num;i++)
{
for(j=0;j<=i;j++)
{
// printf(" \n %lu %lu \n",i,j);
printf(" %lu ",*(*(Matrix+i)+j) );
}
printf("\n");
}
getch();
return(0);
}
C# solution:
public IList<IList<int>> Generate(int numRows) {
var result = new List<IList<int>>();
var item1 = new List<int>();
item1.Add(1);
result.Add(item1);
if (numRows == 1)
return result;
var item2 = new List<int>();
item2.Add(1);
item2.Add(1);
result.Add(item2);
if (numRows == 2)
return result;
var i = 2;
while (i != numRows)
{
var data = result.Last().ToArray();
var n = data.Length;
var item = new int[n + 1];
item[0] = 1;
item[n] = 1;
for (var x = 1; x < n; x++)
item[x] = data[x - 1] + data[x];
result.Add(item);i++;
}
return result;
}
