I have to write a program which asks the user to type in a limit. The program then calculates the sum of consecutive numbers (1 + 2 + 3 + ...) until the sum is at least equal to the limit set by the user.
In addition to the result it should also print out the calculation performed. I should do this with only a while loop, no lists or True conditionals.
limit = int(input("Limit:"))
base = 0
num = 0
calc = " "
while base < limit:
base += num
num += 1
calc += f" + {num}"
print(base)
print(f"The consecutive sum: {calc} = {base}")
So for example, if the input is 10, the output should be 10 and underneath that should be "The consecutive sum: 1 + 2 + 3 + 4 = 10." If the input is 18, the output should be 21 and underneath that should be "The consecutive sum: 1 + 2 + 3 + 4 + 5 + 6 = 21."
Right now I can get it to print the final result (base) and have gotten it to print out the calculation, but it prints out one integer too many. If the input is 10, it prints out 1 + 2 + 3 + 4 + 5 when it should stop before the 5.
I would avoid the while loop and use range instead. You can derive the value of the last term with arithmetic.
If the last term is π, then the sum will be π(π+1)/2, which must be less or equal to the input limit. Resolving this equation to π given the limit, we get that the π is ββ(1 + 8β
limit) β 1) / 2β
So then the program can be:
limit = int(input("Limit:"))
n = int(((1 + 8 * limit) ** 0.5 - 1) / 2)
formula = " + ".join(map(str, range(1, n + 1)))
total = n * (n + 1) // 2
print(f"The consecutive sum: {formula} = {total}")
One way that came to my mind is concatenating values for each iteration:
limit = int(input("Limit:"))
base = 0
num = 1
num_total = 0
calculation = 'The consecutive sum: '
while base < limit:
calculation += f"{num} + "
base += num
num += 1
print(f"{calculation[:-3]} = {base}")
print(base)
#> Limit:18
## The consecutive sum: 1 + 2 + 3 + 4 + 5 + 6 = 21
## 21
The other way is printing value on each iteration without new line in the end (but you have additional + sign in the end here):
limit = int(input("Limit:"))
base = 0
num = 1
num_total = 0
print('The consecutive sum: ', end='')
while base < limit:
print(f"{num} + ", end='')
base += num
num += 1
print(f"= {base}")
print(base)
#> Limit:18
## The consecutive sum: 1 + 2 + 3 + 4 + 5 + 6 + = 21
## 21
There's probably a more efficient way to write this but this was what came to mind...
sum = 0
long_output = []
for i in range(limit + 1):
sum += i
long_output.append(str(i))
print("The consecutive sum: {} = {}".format(' + '.join(long_output), sum))
Keep putting stuff in an list and then join them afterwards. i has to be casted to a str type since join is just for strings
NOTE: the output starts at 0 to account for limit being potentially 0 (I don't know what your constraints are, if any)
EDIT: made updates based on #Copperfield's recommendation
You are/were very close. Try rearranging the follow of execution in your while statements. I also find this assignment hard. Try moving you calc line as the first statement after your 'while'.
One other way is to add an if statement:
if base< num :
calc += f" + {num}"
Here is a example to print the calculation
limit = int(input("Limit:"))
base = 0
num = 1
num_total = 0
msg = ""
while base < limit:
msg = msg + str(num) + "+"
base += num
num += 1
msg = msg[:-1] + "=" + str(limit)
print(msg)
if limit = 21 then the output would be
1+2+3+4+5+6=21
Related
limit = int(input("Limit: "))
allvalue = ""
count = 0
number = 0
while count < limit:
number += 1
count += number
allvalue += str(number) + " + "
print(allvalue)
This is my output 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 +
I want the + symbol only in between the numbers.Not to be in the last or the first.
A likely solution is using " + ".join(), which uses the string method on the " + " to collect the values together
>>> values = "1 2 3 4 5".split()
>>> " + ".join(values)
'1 + 2 + 3 + 4 + 5'
limit = int(input("Limit: "))
allvalue = ""
count = 0
number = 0
while count < limit:
number += 1
count += number
if count != limit:
allvalue += str(number) + " + "
else:
allvalue += str(number)
print(allvalue)
Hope this help.
I would like to share with you a sure shot mathematical solution to this problem.
This problem is a typical variation of Sum of n numbers problem, where the sum depicting limit here is already given as input, instead of n.
import math
limit = int(input("Limit: ")) # n * (n + 1) / 2 >= limit
n = math.ceil( ((1 + 4*2*limit)**0.5 - 1) / 2 ) # ((b^2 - 4ac)^(1/2) - b) / 2a where a = b = 1, c = 2*limit
allValue = " + ".join([str(i) for i in range(1, n+1)])
print(allValue)
You don't need both the number and count variables, and by starting from initial value you can add the + before the number.
limit = int(input("Limit: "))
count = 1
allvalue = str(count)
while count < limit:
count += 1
allvalue += " + " + str(count)
print(allvalue)
You could also try using a for loop.
limit = int(input("Limit: "))
allvalue = ""
for i in range(0, limit):
if i+1 == limit:
allvalue += str(i+1)
else:
allvalue += str(i+1) + "+"
print(allvalue)
Here is simple and easy approach, you can try slice in the result string
print(allvalue[:-2])
code:
limit = int(input("Limit: "))
allvalue = ""
count = 0
number = 0
while count < limit:
number += 1
count += number
allvalue += str(number) + " + "
print(allvalue)
print(allvalue[:-2])
output:
result shared : https://onlinegdb.com/HFC2Hv4wq
Limit: 9
1 + 2 + 3 + 4 +
1 + 2 + 3 + 4
What I have to do is get the user input and add consecutive numbers starting with one using a loop until the sum equals or exceeds the input. It's an exercise, so I'm trying to do this without using the condition True or importing any functions. Just a simple while loop.
This is what I've got.
num = int(input("Limit:"))
base = 0
while base < num:
base += base + 1
print(base)
When I input 21, the printout is 1
3
7
15
31
No idea how to fix. Any advice is greatly appreciated.
Edit: Sorry for not specifying, the expected output should only be the final number, that which exceeds or equals the input. So for instance, if input is 10, output should be 10. If input is 18, output should be 21.
You should calculate consecutive numbers in dedicated variable
Try this
limit = int(input("Limit:"))
base = 0
number = 1
while base < limit:
base += number
number += 1
print(base)
Step through what your code is doing, when given 21 as an input.
num = int(input("Limit:"))
base = 0
while base < num:
base += base + 1
print(base)
We know our initial state is:
num = 21
base = 0
base is less than 21, so we'll add base to 1, then add all of that to base with +=.
num = 21
base = 1
Now, let's keep going:
num = 21
base = 1
num = 21
base = 1 + 1 + 1 = 3
num = 21
base = 3 + 3 + 1 = 7
num = 21
base = 7 + 7 + 1 = 15
number = 21
base = 15 + 15 + 1 = 31
If you want to sum a range of numbers, well... Python makes that really straightforward using a while loop. We need a counter (which we'll update on each loop), the end number, and a sum variable (the name sum is already a built-in function).
num = int(input("Limit:"))
counter = 0
sumNums = 0
while counter < num:
sumNums += counter
count += 1
print(sumNums)
Or we can just sum a range.
print(sum(range(1, num)))
Just because I like math:
num = int(input("Limit:"))
for n in range(1,num):
s = n * (n + 1) / 2
if s >= num:
break
print(int(s))
If you want your expected output to only be the final number, simply unindent the print statement:
limit = int(input("Limit:"))
base = 0
num = 1
# Each time base is less than limit, add base by num (At the first iteration num is 1), and add num by 1
while base < limit:
base += num
num += 1
print(base)
Sample output:
>>> Limit: 18
21
>>> Limit: 10
10
It has to stop before it prints.
number = int(input("Limit: "))
x = 1
y = 1
while y < number:
x +=1
y +=x
print(y)
You must do or base = base + 1 or bas += 1 not both otherwise you sum base + (base + 1) that is wrong.
But you can do it also quickly in the same way:
sum(range(1, num + 1))
I know I need a for loop, I am trying to print the input number(as a maximum) and then print the number of steps it took to reach 1. The current program prints the input number and the nember of steps for that input number, I need it to print every input number and corresponding steps for each number to 1 with related steps. If i input 2 it should say it 2 takes 1 steps then 1 takes 0 steps.
n = int(input('n? '))
n_steps = 0
num=n
while n > 1:
n_steps+=1
if n % 2 == 0:
n = n // 2
else:
n = n * 3 + 1
print(str(num) + ' takes ' + str(n_steps) + ' steps')
are you trying to do something like this?
num = int(input('n? '))
for i in range(num, 0, -1):
n_steps = 0
n = i
while n > 1:
n_steps += 1
if n % 2 == 0:
n = n // 2
else:
n = n * 3 + 1
print(str(i) + ' takes ' + str(n_steps) + ' steps')
So my code is this:
until = int(input("Until: "))
number = 1
result = 1
calculation = ""
while result < until:
number += 1
result = result + number
calculation += f"{number} + "
print(f"Calculated {calculation} = {result}")
And it prints:
Until: 10
Calculated 2 + = 3
Calculated 2 + 3 + = 6
Calculated 2 + 3 + 4 + = 10
and I would like to get rid of the extra plus sign before the equal sign so this 4 + = 10 would look like this 4 = 10
you can use slice strings.
I think the number and result begin with 0 would make more sense, otherwise you will get some weird expression like 2 = 3 or 2 + 3 = 6.
code:
until = int(input("Until: "))
number = 0
result = 0
calculation = ""
while result < until:
number += 1
result = result + number
calculation += f"{number} + "
print(f"Calculated {calculation[:-3]} = {result}")
result:
Until: 10
Calculated 1 = 1
Calculated 1 + 2 = 3
Calculated 1 + 2 + 3 = 6
Calculated 1 + 2 + 3 + 4 = 10
Until: 1
Calculated 1 = 1
You can do something like this:
until = int(input("Until: "))
number = 1
result = 1
calculation = ""
while result < until:
number += 1
result = result + number
if calculation != "":
calculation += " + "
calculation += f"{number}"
print(f"Calculated {calculation} = {result}")
maybe you can add plus sign after print function, like
until = int(input("Until: "))
number = 1
result = 1
calculation = ""
while result < until:
number += 1
result = result + number
calculation += f"{number}"
print(f"Calculated {calculation} = {result}")
calculation += "+"
Just change the order of adding the plus sign
until = int(input("Until: "))
number = 1
result = 1
calculation = ""
while result < until:
number += 1
result = result + number
calculation += f"{number} "
print(f"Calculated {calculation} = {result}")
calculation += "+ "
I made this code about a number and it's power. It will ask a number and it's power and show the output like a horizontal list.. Like
Number = 2
Power = 3.... then output will be like=
1
2
4
Number and power can be +/-.
But I want to sum those numbers like Sum = 7 after it shows
1
2
4
I have no idea how to do it after the output. I am new to programming maybe that's why can't figure out this problem.
Here is the code in Python :
A =float(input("Number:"))
B =float(input("Power:"))
print("Result of Powers:")
i = 0
while i < B:
print(A**i)
i = i + 1
while i >= B:
print(A**i)
i = i - 1
You could simplify this with numpy as follows
import numpy as np
A =float(input("Number:"))
B =int(input("Power:"))
print("Result of Powers:")
power = np.arange(B)
power_result = A ** power
sum_result = np.sum(power_result)
print(power_result)
print(sum_result)
I made B into an int, since I guess it makes sense. Have a look into the numpy documentation to see, what individual functions do.
You can create another variable to store the sum
and to print values on the same line use end=" " argument in the print function
a = float(input("Number:"))
b = int(input("Power:"))
sum = 0.0
i = 0
while b < 0:
ans = a**i
i = i - 1
print(ans, end=" ")
sum = sum + ans
b += 1
while b >= 0:
ans = a**i
i = i + 1
print(ans, end=" ")
sum = sum + ans
b -= 1
print("\nSum = " + str(sum))
I'm not sure what you want to achieve with the second loop. This works:
A =float(input("Number:"))
B =float(input("Power:"))
print("Result of Powers:")
i = 0
n_sum = 0
while i < B:
n_sum += A**i
print(A**i)
i = i + 1
while i >= B:
n_sum += A**i
print(A**i)
i = i - 1
print(n_sum)