Lưu ý rằng các số Fibonacci bắt đầu với 0 và 1, không phải 1 và 2. Điều này sẽ không ảnh hưởng đến kết quả của bạn, nhưng nó giúp xử lý các số dễ dàng hơn. Bắt đầu bằng cách viết một hàm trình tạo mang lại tất cả các số Fibonacci (cuối cùng). def fib():
a = 0
b = 1
while True:
yield a
a, b = b, a + b
Bạn không phải kiểm tra một giá trị nếu nó là chẵn, bởi vì các số chẵn có vẻ rất dự đoán trong chuỗi: 0 1 1 2 3 5 8 13 21 34 ...
Bắt đầu với giá trị thứ nhất, mỗi giá trị thứ ba đều là. Cho máy phát điện f = fib() # All the Fibonacci numbers
Sau đó, bạn có thể nhận được câu trả lời của mình trong ba bước dễ dàng: from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
Bạn không cần thủ thuật trị giá thứ ba, nhưng nó hiệu quả hơn một chút so với evens = filter(lambda x: x % 2 == 0, f)
f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
2 Recurrence for Even Fibonacci sequence is:
EFn = 4EFn-1 + EFn-2
with seed values
EF0 = 0 and EF1 = 2.
EFn represents n'th term in Even Fibonacci sequence.6
The first few terms of Fibonacci Numbers are, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233 ,… (Even numbers are highlighted).
Examples :
Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. PHP
An efficient solution is based on the below recursive formula for even Fibonacci Numbers
Recurrence for Even Fibonacci sequence is:
EFn = 4EFn-1 + EFn-2
with seed values
EF0 = 0 and EF1 = 2.
EFn represents n'th term in Even Fibonacci sequence.f = fib() # All the Fibonacci numbers
86 0 1 1 2 3 5 8 13 21 34 ...
3f = fib() # All the Fibonacci numbers
88using0
So while iterating over Fibonacci numbers, we only generate even Fibonacci numbers.
C++#include<iostream>
using
0 1 1 2 3 5 8 13 21 34 ...
0 0 1 1 2 3 5 8 13 21 34 ...
10 1 1 2 3 5 8 13 21 34 ...
2 0 1 1 2 3 5 8 13 21 34 ...
30 1 1 2 3 5 8 13 21 34 ...
2 0 1 1 2 3 5 8 13 21 34 ...
50 1 1 2 3 5 8 13 21 34 ...
60 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
8 0 1 1 2 3 5 8 13 21 34 ...
9f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
1 f = fib() # All the Fibonacci numbers
20 1 1 2 3 5 8 13 21 34 ...
7f = fib() # All the Fibonacci numbers
4 f = fib() # All the Fibonacci numbers
4 0 1 1 2 3 5 8 13 21 34 ...
2 f = fib() # All the Fibonacci numbers
70 1 1 2 3 5 8 13 21 34 ...
7f = fib() # All the Fibonacci numbers
4 f = fib() # All the Fibonacci numbers
4 0 1 1 2 3 5 8 13 21 34 ...
2 from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
20 1 1 2 3 5 8 13 21 34 ...
7from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
4 from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
50 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
6f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
4 f = fib() # All the Fibonacci numbers
4 0 1 1 2 3 5 8 13 21 34 ...
2 evens = filter(lambda x: x % 2 == 0, f)
2f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
8 evens = filter(lambda x: x % 2 == 0, f)
5evens = filter(lambda x: x % 2 == 0, f)
6evens = filter(lambda x: x % 2 == 0, f)
7evens = filter(lambda x: x % 2 == 0, f)
8f = fib() # All the Fibonacci numbers
0Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 0f = fib() # All the Fibonacci numbers
0Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 2f = fib() # All the Fibonacci numbers
0Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 40 1 1 2 3 5 8 13 21 34 ...
7Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 60 1 1 2 3 5 8 13 21 34 ...
7f = fib() # All the Fibonacci numbers
1 Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 9Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 60 1 1 2 3 5 8 13 21 34 ...
2 Recurrence for Even Fibonacci sequence is:
EFn = 4EFn-1 + EFn-2
with seed values
EF0 = 0 and EF1 = 2.
EFn represents n'th term in Even Fibonacci sequence.20 1 1 2 3 5 8 13 21 34 ...
60 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
2 Recurrence for Even Fibonacci sequence is:
EFn = 4EFn-1 + EFn-2
with seed values
EF0 = 0 and EF1 = 2.
EFn represents n'th term in Even Fibonacci sequence.60 1 1 2 3 5 8 13 21 34 ...
7Recurrence for Even Fibonacci sequence is:
EFn = 4EFn-1 + EFn-2
with seed values
EF0 = 0 and EF1 = 2.
EFn represents n'th term in Even Fibonacci sequence.80 1 1 2 3 5 8 13 21 34 ...
7f = fib() # All the Fibonacci numbers
1 f = fib() # All the Fibonacci numbers
2Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 6Java188 3 188 4188 5 188 60 1 1 2 3 5 8 13 21 34 ...
60 1 1 2 3 5 8 13 21 34 ...
7188 9 0 1 1 2 3 5 8 13 21 34 ...
2 0 1 1 2 3 5 8 13 21 34 ...
30 1 1 2 3 5 8 13 21 34 ...
2 0 1 1 2 3 5 8 13 21 34 ...
50 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
6f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
8 #include<iostream>8#include<iostream>9using0evens = filter(lambda x: x % 2 == 0, f)
6f = fib() # All the Fibonacci numbers
1 using3evens = filter(lambda x: x % 2 == 0, f)
8f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
4 using7using3using9#include<iostream>9evens = filter(lambda x: x % 2 == 0, f)
8f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
4 from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
2f = fib() # All the Fibonacci numbers
0from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
4 from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
5f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
6evens = filter(lambda x: x % 2 == 0, f)
6f = fib() # All the Fibonacci numbers
4 0 1 1 2 3 5 8 13 21 34 ...
122____113 0 1 1 2 3 5 8 13 21 34 ...
14evens = filter(lambda x: x % 2 == 0, f)
60 1 1 2 3 5 8 13 21 34 ...
8 evens = filter(lambda x: x % 2 == 0, f)
50 1 1 2 3 5 8 13 21 34 ...
18evens = filter(lambda x: x % 2 == 0, f)
7evens = filter(lambda x: x % 2 == 0, f)
8evens = filter(lambda x: x % 2 == 0, f)
6Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 0evens = filter(lambda x: x % 2 == 0, f)
6Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 2evens = filter(lambda x: x % 2 == 0, f)
6Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 4f = fib() # All the Fibonacci numbers
0Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 6f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
10 1 1 2 3 5 8 13 21 34 ...
310 1 1 2 3 5 8 13 21 34 ...
20 1 1 2 3 5 8 13 21 34 ...
330 1 1 2 3 5 8 13 21 34 ...
7Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 60 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
37 188 9 0 1 1 2 3 5 8 13 21 34 ...
39 0 1 1 2 3 5 8 13 21 34 ...
400 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
6f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
2 0 1 1 2 3 5 8 13 21 34 ...
450 1 1 2 3 5 8 13 21 34 ...
46evens = filter(lambda x: x % 2 == 0, f)
8f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
490 1 1 2 3 5 8 13 21 34 ...
7Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 6Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 6Python30 1 1 2 3 5 8 13 21 34 ...
53 0 1 1 2 3 5 8 13 21 34 ...
540 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
8 #include<iostream>8#include<iostream>90 1 1 2 3 5 8 13 21 34 ...
59f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
1 using30 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
640 1 1 2 3 5 8 13 21 34 ...
65 using30 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
680 1 1 2 3 5 8 13 21 34 ...
65 #include<iostream>90 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
720 1 1 2 3 5 8 13 21 34 ...
65 0 1 1 2 3 5 8 13 21 34 ...
640 1 1 2 3 5 8 13 21 34 ...
75 0 1 1 2 3 5 8 13 21 34 ...
760 1 1 2 3 5 8 13 21 34 ...
7from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
4 0 1 1 2 3 5 8 13 21 34 ...
790 1 1 2 3 5 8 13 21 34 ...
65 0 1 1 2 3 5 8 13 21 34 ...
81f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
830 1 1 2 3 5 8 13 21 34 ...
65 0 1 1 2 3 5 8 13 21 34 ...
13 0 1 1 2 3 5 8 13 21 34 ...
86 0 1 1 2 3 5 8 13 21 34 ...
680 1 1 2 3 5 8 13 21 34 ...
75 0 1 1 2 3 5 8 13 21 34 ...
89f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
8 0 1 1 2 3 5 8 13 21 34 ...
92evens = filter(lambda x: x % 2 == 0, f)
6evens = filter(lambda x: x % 2 == 0, f)
7f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
640 1 1 2 3 5 8 13 21 34 ...
65 0 1 1 2 3 5 8 13 21 34 ...
76f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
680 1 1 2 3 5 8 13 21 34 ...
65 f = fib() # All the Fibonacci numbers
02f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
040 1 1 2 3 5 8 13 21 34 ...
65 f = fib() # All the Fibonacci numbers
040 1 1 2 3 5 8 13 21 34 ...
75 0 1 1 2 3 5 8 13 21 34 ...
760 1 1 2 3 5 8 13 21 34 ...
7f = fib() # All the Fibonacci numbers
1 0 1 1 2 3 5 8 13 21 34 ...
72f = fib() # All the Fibonacci numbers
120 1 1 2 3 5 8 13 21 34 ...
65 0 1 1 2 3 5 8 13 21 34 ...
46f = fib() # All the Fibonacci numbers
15f = fib() # All the Fibonacci numbers
16C#using
f = fib() # All the Fibonacci numbers
18188 5 f = fib() # All the Fibonacci numbers
200 1 1 2 3 5 8 13 21 34 ...
7188 9 0 1 1 2 3 5 8 13 21 34 ...
2 0 1 1 2 3 5 8 13 21 34 ...
30 1 1 2 3 5 8 13 21 34 ...
2 0 1 1 2 3 5 8 13 21 34 ...
50 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
6f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
8 #include<iostream>8#include<iostream>9using0evens = filter(lambda x: x % 2 == 0, f)
6f = fib() # All the Fibonacci numbers
1 using3evens = filter(lambda x: x % 2 == 0, f)
8f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
4 using7using3using9#include<iostream>9evens = filter(lambda x: x % 2 == 0, f)
8f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
4 from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
2f = fib() # All the Fibonacci numbers
0from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
4 from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
5f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
6evens = filter(lambda x: x % 2 == 0, f)
6f = fib() # All the Fibonacci numbers
4 0 1 1 2 3 5 8 13 21 34 ...
122____113 0 1 1 2 3 5 8 13 21 34 ...
14evens = filter(lambda x: x % 2 == 0, f)
60 1 1 2 3 5 8 13 21 34 ...
8 evens = filter(lambda x: x % 2 == 0, f)
50 1 1 2 3 5 8 13 21 34 ...
18evens = filter(lambda x: x % 2 == 0, f)
7evens = filter(lambda x: x % 2 == 0, f)
8evens = filter(lambda x: x % 2 == 0, f)
6Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 0evens = filter(lambda x: x % 2 == 0, f)
6Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 2evens = filter(lambda x: x % 2 == 0, f)
6Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 4f = fib() # All the Fibonacci numbers
0Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 6f = fib() # All the Fibonacci numbers
0Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 60 1 1 2 3 5 8 13 21 34 ...
7Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 60 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
37 188 9 0 1 1 2 3 5 8 13 21 34 ...
39 0 1 1 2 3 5 8 13 21 34 ...
400 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
6f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
2 0 1 1 2 3 5 8 13 21 34 ...
450 1 1 2 3 5 8 13 21 34 ...
46evens = filter(lambda x: x % 2 == 0, f)
8f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
810 1 1 2 3 5 8 13 21 34 ...
7Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 6Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 60 1 1 2 3 5 8 13 21 34 ...53 0 1 1 2 3 5 8 13 21 34 ...54f = fib() # All the Fibonacci numbers
850 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
8 #include<iostream>8#include<iostream>90 1 1 2 3 5 8 13 21 34 ...
590 1 1 2 3 5 8 13 21 34 ...
6f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
1 using3f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
1 f = fib() # All the Fibonacci numbers
20 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
640 1 1 2 3 5 8 13 21 34 ...
65 using30 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
680 1 1 2 3 5 8 13 21 34 ...
65 #include<iostream>90 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
720 1 1 2 3 5 8 13 21 34 ...
65 0 1 1 2 3 5 8 13 21 34 ...
640 1 1 2 3 5 8 13 21 34 ...
75 0 1 1 2 3 5 8 13 21 34 ...
760 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
60 1 1 2 3 5 8 13 21 34 ...
7from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
4 0 1 1 2 3 5 8 13 21 34 ...
790 1 1 2 3 5 8 13 21 34 ...
65 0 1 1 2 3 5 8 13 21 34 ...
81f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
830 1 1 2 3 5 8 13 21 34 ...
65 0 1 1 2 3 5 8 13 21 34 ...
13 0 1 1 2 3 5 8 13 21 34 ...
86 0 1 1 2 3 5 8 13 21 34 ...
680 1 1 2 3 5 8 13 21 34 ...
75 0 1 1 2 3 5 8 13 21 34 ...
89evens = filter(lambda x: x % 2 == 0, f)
6evens = filter(lambda x: x % 2 == 0, f)
7evens = filter(lambda x: x % 2 == 0, f)
8f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
8 0 1 1 2 3 5 8 13 21 34 ...
92f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
640 1 1 2 3 5 8 13 21 34 ...
65 0 1 1 2 3 5 8 13 21 34 ...
76f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
680 1 1 2 3 5 8 13 21 34 ...
65 f = fib() # All the Fibonacci numbers
020 1 1 2 3 5 8 13 21 34 ...
7Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 6f = fib() # All the Fibonacci numbers
0f = fib() # All the Fibonacci numbers
040 1 1 2 3 5 8 13 21 34 ...
65 f = fib() # All the Fibonacci numbers
040 1 1 2 3 5 8 13 21 34 ...
75 0 1 1 2 3 5 8 13 21 34 ...
76Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 60 1 1 2 3 5 8 13 21 34 ...
7f = fib() # All the Fibonacci numbers
1 0 1 1 2 3 5 8 13 21 34 ...
72
from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
61from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
62f = fib() # All the Fibonacci numbers
88from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
64from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
65f = fib() # All the Fibonacci numbers
120 1 1 2 3 5 8 13 21 34 ...65 0 1 1 2 3 5 8 13 21 34 ...46from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
66using
f = fib() # All the Fibonacci numbers
180 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
6f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
8 #include<iostream>8#include<iostream>9using0evens = filter(lambda x: x % 2 == 0, f)
6f = fib() # All the Fibonacci numbers
1 using3evens = filter(lambda x: x % 2 == 0, f)
8f = fib() # All the Fibonacci numbers
0from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
79f = fib() # All the Fibonacci numbers
0from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
81f = fib() # All the Fibonacci numbers
0from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
4 from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
5f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
6evens = filter(lambda x: x % 2 == 0, f)
6from itertools import islice, takewhile
evens = islice(f, 0, None, 3) # All the even Fibonacci numbers
small = takewhile(lambda x: x <= 4000000, evens) # Just the ones under 4,000,000
result = sum(small)
88evens = filter(lambda x: x % 2 == 0, f)
60 1 1 2 3 5 8 13 21 34 ...
8 evens = filter(lambda x: x % 2 == 0, f)
50 1 1 2 3 5 8 13 21 34 ...
18evens = filter(lambda x: x % 2 == 0, f)
7evens = filter(lambda x: x % 2 == 0, f)
8evens = filter(lambda x: x % 2 == 0, f)
6Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 0evens = filter(lambda x: x % 2 == 0, f)
6Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 2evens = filter(lambda x: x % 2 == 0, f)
6Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 4
f = fib() # All the Fibonacci numbers
0Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 6f = fib() # All the Fibonacci numbers
0Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 60 1 1 2 3 5 8 13 21 34 ...
7Input : limit = 8
Output : 10
Explanation : 2 + 8 = 10
Input : limit = 400;
Output : 188.
Explanation : 2 + 8 + 34 + 144 = 188. 6f = fib() # All the Fibonacci numbers
0evens = filter(lambda x: x % 2 == 0, f)
09f = fib() # All the Fibonacci numbers
0evens = filter(lambda x: x % 2 == 0, f)
11evens = filter(lambda x: x % 2 == 0, f)
120 1 1 2 3 5 8 13 21 34 ...
70 1 1 2 3 5 8 13 21 34 ...
37 188 9 0 1 1 2 3 5 8 13 21 34 ...
39 0 1 1 2 3 5 8 13 21 34 ...
40
188 f = fib() # All the Fibonacci numbers
00 1 1 2 3 5 8 13 21 34 ...
2 0 1 1 2 3 5 8 13 21 34 ...
450 1 1 2 3 5 8 13 21 34 ...
46evens = filter(lambda x: x % 2 == 0, f)
8O(log4(n)) (where n = limit, as here we multiply prev even fib. no. with 4 to find next even fib. no. so this will lead time complexity to O(log4(n)) )
0 1 1 2 3 5 8 13 21 34 ...
53 0 1 1 2 3 5 8 13 21 34 ...
54 O(1)
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