Guys heres my problem:
I am trying to read an integer from the user(e.g. 12345)
How can i check if the pattern "34" exists in the first integer?
My constraint is that i cannot convert it to string and cannot use arrays.
Here is what i managed to write to print some of the patterns that exists in 12345:
import math
int1 = int(input("input an integer: "))
#I used this to find out how many digits are in the integer
count = math.ceil(math.log10(int1))
for i in range(count):
print (int1 % (10 ** (i+1)))
for i in range(count):
print (int1 // (10 ** (i+1)))
Since this seems to be homework, I won't provide an answer, but only a rough hint.
Hint: extract each digit of the number using divmod(n, 10), which returns n without the last digit and the last digit of n. Hold the current digit and the previous digit in variables and compare them with the pattern, 34, each time a new a digit is extracted.
Related
here is my code... It's considering only 8 and 88 among 1 to 100 which aren't karpekar numbers...failing at if condition(s==n)
def kaprekarNumbers(p, q):
for i in range(p,q+1):
n=i
m=str(i*i);
sl1=m[:int(len(m)/2)]
sl2=m[int(len(m)/2):]
if(sl2==""):
sl2=0
s=int(sl2)+int(sl2)
print(s==n)
if s==n:
print(i)
Using strings to process numbers is not usually a good idea.
You can get the number of digits of a number n with
math.ceil(math.log10(n))
You can get the last a digits of a number n with
n % a
(See: How does % work in Python?)
You can get the first a digits of a number n with
p // (10 ** a)
Those would be useful for base-10 Kaprekar numbers.
[Please note, I do not have a copy of Python to hand to check those.]
Can anyone please give me instruction how to write the program using this algorithm?
To convert binary integer to decimal, start from the left. Take your current total, multiply it by two and add the current digit. Continue until there are no more digits left.
First need to input the binary number as a string then select one by one digits of binary number
num=input("Enter the binary integer Number: ")
num=str(num)
decimal=''
rem=0
i=0
i=int(i)
dig=num[i]
dig=int(dig)
rem=(rem*2)+dig
i=i+1
dig=num[i]
dig=int(dig)
rem=(rem*2)+dig
i=i+1
dig=num[i]
dig=int(dig)
rem=(rem*2)+dig
i=i+1
dig=num[i]
dig=int(dig)
rem=(rem*2)+dig
i=i+1
decimal=int(rem)
print(decimal)
This code only calculate 4 digits of binary numbers. How can i add a while loop in this code?
Yes, you can put that in a loop:
binary = input("Enter the binary integer Number: ")
decimal = 0
for dig in binary:
decimal = decimal*2 + int(dig)
print(decimal)
Note that in Python 3, input already returns a string type value, so you don't need to convert it with str().
You can use the int() function:
binary_string = input('Please input a binary number: ')
print(int(binary_string, 2))
A one liner, just because it is possible:
print(int(input('Please input a binary number: '), 2))
But if you really want to do this with a loop, you can do:
binary_string = input('Please input a binary number: ')
result = 0
multiplier = 1
for digit in binary_string[::-1]:
result += int(digit) * multiplier
multiplier *= 2
print(result)
How do I call out a particular digit from a number. For example: bringing out 6 from 768, then using 6 to multiply 3. I've tried using the code below, but it does not work.
digits = []
digits = str(input("no:"))
print (int(digits[1] * 5))
If my input is 234 since the value in[1] is 3, how can I multiply the 3 by 5?
input() returns a string (wether or not you explicitly convert it to str() again), so digits[1] is still a single character string.
You need to convert that single digit to an integer with int(), not the result of the multiplication:
print (int(digits[1]) * 5)
All I did was move a ) parenthesis there.
Your mistake was to multiply the single-character string; multiplying a string by n produces that string repeated n times.
digits[1] = '3' so digits[1] * 5 = '33333'. You want int(digits[1]) * 5.
I'm trying to make a program that will tell the user if the inputted number is either a prime number or not. I would like to know how to format it to where it will return the remainder. I have the following .py file that I made, but I keep getting error "not all arguments converted during string formatting":
i = 2
x = input("Input your proposed prime number now:\n")
number = x % i
print (number)
#Rishav had incorrect formatting, try:
x = int(input(Input your proposed prime number now:\n"))
if you are working with decimals, you can use:
y = float(input("Input a decimal > "))
input returns a string in Python3. Use :
x = int(input("Input your proposed prime number now:\n")
Many languages have functions for converting string to integer and vice versa. So what happens there? What algorithm is being executed during conversion?
I don't ask in specific language because I think it should be similar in all of them.
To convert a string to an integer, take each character in turn and if it's in the range '0' through '9', convert it to its decimal equivalent. Usually that's simply subtracting the character value of '0'. Now multiply any previous results by 10 and add the new value. Repeat until there are no digits left. If there was a leading '-' minus sign, invert the result.
To convert an integer to a string, start by inverting the number if it is negative. Divide the integer by 10 and save the remainder. Convert the remainder to a character by adding the character value of '0'. Push this to the beginning of the string; now repeat with the value that you obtained from the division. Repeat until the divided value is zero. Put out a leading '-' minus sign if the number started out negative.
Here are concrete implementations in Python, which in my opinion is the language closest to pseudo-code.
def string_to_int(s):
i = 0
sign = 1
if s[0] == '-':
sign = -1
s = s[1:]
for c in s:
if not ('0' <= c <= '9'):
raise ValueError
i = 10 * i + ord(c) - ord('0')
return sign * i
def int_to_string(i):
s = ''
sign = ''
if i < 0:
sign = '-'
i = -i
while True:
remainder = i % 10
i = i / 10
s = chr(ord('0') + remainder) + s
if i == 0:
break
return sign + s
I wouldn't call it an algorithm per se, but depending on the language it will involve the conversion of characters into their integral equivalent. Many languages will either stop on the first character that cannot be represented as an integer (e.g. the letter a), will blindly convert all characters into their ASCII value (e.g. the letter a becomes 97), or will ignore characters that cannot be represented as integers and only convert the ones that can - or return 0 / empty. You have to get more specific on the framework/language to provide more information.
String to integer:
Many (most) languages represent strings, on some level or another, as an array (or list) of characters, which are also short integers. Map the ones corresponding to number characters to their number value. For example, '0' in ascii is represented by 48. So you map 48 to 0, 49 to 1, and so on to 9.
Starting from the left, you multiply your current total by 10, add the next character's value, and move on. (You can make a larger or smaller map, change the number you multiply by at each step, and convert strings of any base you like.)
Integer to string is a longer process involving base conversion to 10. I suppose that since most integers have limited bits (32 or 64, usually), you know that it will come to a certain number of characters at most in a string (20?). So you can set up your own adder and iterate through each place for each bit after calculating its value (2^place).