# Python Program to Print Double the Number Pattern

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Given the number of rows, the task is to print Double the Number Pattern in C, C++, and Python.

Examples:

Example1:

Input:

Given number of rows = 10

Output:

1
2 1
4 2 1
8 4 2 1
16 8 4 2 1
32 16 8 4 2 1
64 32 16 8 4 2 1
128 64 32 16 8 4 2 1
256 128 64 32 16 8 4 2 1

Example2:

Input:

Given number of rows = 7

Output:

  1
2   1
4   2   1
8   4   2   1
16   8   4   2   1
32  16   8   4   2   1

## Program to Print Double the Number Pattern in C, C++, and Python

Below are the ways to print Double the Number Pattern in C, C++, and Python.

### Method #1: Using For Loop (Static Input)

Approach:

• Give the number of rows as static input and store it in a variable.
• Loop from 1 to the number of rows using For loop.
• Loop from iterator value of the parent For loop -1 to 0 in decreasing order using another for loop(Nested For loop).
• Print the 2 power n value with space where n is the value of the inner for loop.
• Print the Newline character after the end of the inner loop.
• The Exit of the Program.

1) Python Implementation

Below is the implementation:

# Give the number of rows as static input and store it in a variable.
numbrrows = 7
# Loop from 1 to the number of rows using For loop.
for m in range(1, numbrrows):
# Loop from iterator value of the parent For loop -1 to 0
# in decreasing order using another for loop(Nested For loop).
for n in range(m - 1, -1, -1):
# Print the 2 power n value with space where n is the value of the inner for loop.
print(2**n, end=' ')
# Print the Newline character after the end of the inner loop.
print()


Output:

  1
2   1
4   2   1
8   4   2   1
16   8   4   2   1
32  16   8   4   2   1

2) C++ Implementation

Below is the implementation:

#include <iostream>
#include <math.h>
using namespace std;

int main()
{

// Give the number of rows as static input and store it
// in a variable.
int numbrrows = 10;
// Loop from 1 to the number of rows using For loop.
for (int m = 1; m < numbrrows; m++) {
/*  Loop from iterator value of the parent For loop
-1 to 0 in decreasing order using another for
loop(Nested For loop)*/
for (int n = m - 1; n >= 0; n--) {
// Print the 2 power n value with space where n
// is the value of the inner for loop.
cout << pow(2, n) << " ";
}
// Print the Newline character after the end of the
// inner loop.
cout << endl;
}
return 0;
}

Output:

1
2 1
4 2 1
8 4 2 1
16 8 4 2 1
32 16 8 4 2 1
64 32 16 8 4 2 1
128 64 32 16 8 4 2 1
256 128 64 32 16 8 4 2 1

3) C Implementation

Below is the implementation:

#include <math.h>
#include <stdio.h>
int main()
{

// Give the number of rows as static input and store it
// in a variable.
int numbrrows = 4;
// Loop from 1 to the number of rows using For loop.
for (int m = 1; m < numbrrows; m++) {
/*  Loop from iterator value of the parent For loop
-1 to 0 in decreasing order using another for
loop(Nested For loop)*/
for (int n = m - 1; n >= 0; n--) {
// Print the 2 power n value with space where n
// is the value of the inner for loop.
int powervalu = pow(2, n);
printf("%d ", powervalu);
}
// Print the Newline character after the end of the
// inner loop.
printf("\n");
}
return 0;
}

Output:

1
2 1
4 2 1

### Method #2: Using For Loop (User Input)

Approach:

• Give the number of rows as user input and store it in a variable.
• Loop from 1 to the number of rows using For loop.
• Loop from iterator value of the parent For loop -1 to 0 in decreasing order using another for loop(Nested For loop).
• Print the 2 power n value with space where n is the value of the inner for loop.
• Print the Newline character after the end of the inner loop.
• The Exit of the Program.

1) Python Implementation

Give the number of rows as user input using int(input()) and store it in a variable.

Below is the implementation:

# Give the number of rows as user input using int(input()) and store it in a variable.
numbrrows = int(input('Enter some random number of rows = '))
# Loop from 1 to the number of rows using For loop.
for m in range(1, numbrrows):
# Loop from iterator value of the parent For loop -1 to 0
# in decreasing order using another for loop(Nested For loop).
for n in range(m - 1, -1, -1):
# Print the 2 power n value with space where n is the value of the inner for loop.
print(2**n, end=' ')
# Print the Newline character after the end of the inner loop.
print()


Output:

Enter some random number of rows = 8
1
2 1
4 2 1
8 4 2 1
16 8 4 2 1
32 16 8 4 2 1
64 32 16 8 4 2 1

2) C++ Implementation

Give the number of rows as user input using cin and store it in a variable.

Below is the implementation:

#include <iostream>
#include <math.h>
using namespace std;
int main()
{

// Give the number of rows as user input using
// int(input()) and store it in a variable.
int numbrrows;
cin >> numbrrows;
// Loop from 1 to the number of rows using For loop.
for (int m = 1; m < numbrrows; m++) {
/*  Loop from iterator value of the parent For loop
-1 to 0 in decreasing order using another for
loop(Nested For loop)*/
for (int n = m - 1; n >= 0; n--) {
// Print the 2 power n value with space where n
// is the value of the inner for loop.
cout << pow(2, n) << " ";
}
// Print the Newline character after the end of the
// inner loop.
cout << endl;
}

return 0;
}

Output:

5
1
2 1
4 2 1
8 4 2 1

3) C Implementation

Give the number of rows as user input using scanf and store it in a variable.

Below is the implementation:

#include <math.h>
#include <stdio.h>
int main()
{

// Give the number of rows as user input using scanf and
// store it in a variable.
int numbrrows;
scanf("%d", &numbrrows);
// Loop from 1 to the number of rows using For loop.
for (int m = 1; m < numbrrows; m++) {
/*  Loop from iterator value of the parent For loop
-1 to 0 in decreasing order using another for
loop(Nested For loop)*/
for (int n = m - 1; n >= 0; n--) {
// Print the 2 power n value with space where n
// is the value of the inner for loop.
int powervalu = pow(2, n);
printf("%d ", powervalu);
}
// Print the Newline character after the end of the
// inner loop.
printf("\n");
}
return 0;
}

Output:

5
1
2 1
4 2 1
8 4 2 1

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