List Comprehensions | HackerRank

Goal

Print a list of all possible coordinates given by (i, j, k) on a 3D grid where the sum of i + j + k is not equal to n.

Solution

You can simply make a condition statement {(i + j + k) != n} to append all (i,j,k) combinations into list and print the list. 

There are two simple ways to solve this problem. You can use simply multiple loops, but you can use easily loop comprehensions. 

1) The for statement

# List Comprehensions

if __name__ == '__main__':
    x = int(input())
    y = int(input())
    z = int(input())
    n = int(input())

    results = []

    for i in range( x + 1):
        for j in range( y + 1):
            for k in range(z + 1):
                if (i + j + k) != n:
                    results.append([i, j, k])


    print(results)

2) List Comprehension

# List Comprehensions

if __name__ == '__main__':
    x = int(input())
    y = int(input())
    z = int(input())
    n = int(input())

    results = [[i,j,k] for i in range(x+1) for j in range(y+1) for k in range(z+1) if i+j+k != n]

    print(results)

Print Function | HackerRank

Goal

Print the list of integers from 1 through give n as a string, without spaces

Solution

To solve this problem, you can use for statement and str class to convert integer value to string object. 

# Print Function

if __name__ == '__main__':
    n = int(input())
    
    number = ""
    for i in range(1, n+1, 1):
        number += str(i)
        
    print(int(number))

Write a function | HackerRank

Goal

This task is to return true if a give year is a leap year, otherwise return false

Solution

There are three main conditions to check leap year:

1. It can be evenly divided by 4 - leap year

2. It can be evenly divided by 100, it is NOT a leap year, unless it is evenly disivible by 400 - leap year

3. Otherwise it is not a leap year.

These conditions can be shown in this code.

# Write a function

def is_leap(year):
    leap = False
    
    # Write your logic here
    if year % 4 == 0:
        if year % 100 == 0:
            if year % 400 == 0:
                leap = True
            else : 
                leap = False
        else:  
            leap = True
        
    else:
        leap = False
    
    return leap

year = int(input())
print(is_leap(year))

Loops | HackerRank

Goal

Solution

If you know for statement in python, it woul be very easy task.

# Loops

if __name__ == '__main__':
    n = int(input())
    
    for i in range(n):
        print(i * i)

Python: Division | HackerRank

Goal

1. Read two integers each line.

2. print (a//b) in first line.

3. print (a/b) in second line.

Solution

Use input() function to read two integer values. But don't forget to convert input return value into integer value. 

# Python: Division

if __name__ == '__main__':
    a = int(input())
    b = int(input())
    
    print(a // b)
    print(a / b)

Arithmetic Operators | HackerRank

Goal

1. Read two integers from STDIN.

2. Solve tasks to use arithmetic operators. 

Solution

You can read values by using input() function. The important thing is to convert input() value into integer type because Input() function returns string value from input. 

After read two integer values, you can calculate vaules for each task.

# Arithmetic Operators

if __name__ == '__main__':
    a = int(input())
    b = int(input())
    
    sum = a + b
    difference = a - b
    product = a * b
    
    print(sum)
    print(difference)
    print(product)

Python If-Else | HackerRank

Goal

You need to print "Weird" if the number is weird in under condition. Otherweise, print "Not Weird". 

Solution

You can follow what conditions say, then it would be easy.

# Python If-Else

import math
import os
import random
import re
import sys


if __name__ == '__main__':
    n = int(input().strip())
    
    if (n % 2) !=0 : 
        print('Weird')
    else:
        if (n >=2 and n <=5):
            print('Not Weird')
        
        elif (n >=6 and n <=20):
            print('Weird')
            
        else:
            print('Not Weird')

Say "Hello, World!" With Python | HackerRank

Goal

Print "Hello, World!" to stdout. 

Solution

You can use print function to print the specificed message. 

# Say "Hello, World!" With Python

if __name__ == '__main__':
    print("Hello, World!")