On solving Project Euler

[Jeff Calc 84]

Hello! As I'm a serious (read: terrible) math and computer enthusiast, I've decided to solve every problem on Project Euler using Python.

[Jeff Calc 84]

P001:
Link: https://pe-cn.github.io/1/

Code: Select all

s=0
for i in range(1,1000):
    if i%3==0:
        s+=i
    if i%5==0:
        s+=i
    if i%10==0:
        s-=i
print(s)

[Jeff Calc 84]

P002:
Link:https://pe-cn.github.io/2/

Code: Select all

a=1
b=1
s=0
while a<4000000:
    s+=a+b
    c=a+2*b
    b=2*a+3*b
    a=c
print(s)

[Jeff Calc 84]

p004:
Link:https://pe-cn.github.io/4/

Code: Select all

def isPal(a):
    b=str(a)
    if b==b[::-1]:
        return True
    return False

s=0
for i in range(100,1000):
    for j in range(i,1000):
        if isPal(i*j) and i*j>s:
            s=i*j
print(s)

Note: skipping p003 for now

[Jeff Calc 84]

p005:
Link:https://pe-cn.github.io/5/

Code: Select all

import math
s=1
primes=[2,3,5,7,11,13,17,19]
for i in range(0,len(primes)):
    s*=pow(primes[i],math.floor(math.log(20,primes[i])))
print(s)

[Jeff Calc 84]

p006:
Link:https://pe-cn.github.io/6/

Code: Select all

a=0
s=0
for i in range(1,101):
    a+=i*i
    s+=i
s=s*s
print(abs(s-a))

[Jeff Calc 84]

p008:
Link:pe-cn.github.io/8/

Code: Select all

s="7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450"
a=0
for i in range(0,len(s)-13):
    t=int(s[i])*int(s[i+1])*int(s[i+2])*int(s[i+3])*int(s[i+4])*int(s[i+5])*int(s[i+6])*int(s[i+7])*int(s[i+8])*int(s[i+9])*int(s[i+10])*int(s[i+11])*int(s[i+12])
    if t>a:
        a=t
print(a)

This is just stupid...

[Jeff Calc 84]

p009:
Link:pe-cn.github.io/9/

Code: Select all

for a in range(1,1001):
    for b in range(a+1,1001-a):
        if a*a+b*b-(1000-a-b)*(1000-a-b)==0:
            print(a*b*(1000-a-b))

Really, is Python THAT fast? (or is my computer fast?)