Project Euler - 006

icymirror

Problem 006:
The sum of the squares of the first ten natural numbers is,
1^2 + 2^2 + ... + 10^2 = 385
The square of the sum of the first ten natural numbers is,
(1 + 2 + ... + 10)^2 = 55^2 = 3025
Hence the difference between the sum of the squares of the first ten natural numbers and the square of the sum is 3025 − 385 = 2640.
Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum.

问题6：
前十个自然数的平方和：1^2 + 2^2 + ... + 10^2 = 385
前十个自然数的和的平方是：(1 + 2 + ... + 10) ^ 2 = 55^2 = 3025
所以两者之差是：3025-385=2640
现在，试求出前一百个自然数的和的平方与平方和的差。

代码：

1. 
   
2. package main
   
3. 
   
4. import (
   
5.         "fmt"
   
6. )
   
7. 
   
8. func SumOfArithmeticSequence(min, max, step int) int {
   
9.         return (min + max) * ((max - min + 1) / step) / 2
   
10. }
    
11. 
    
12. func SumOfSquareSequence(min, max int) int {
    
13.         result := 0
    
14.         for index := min; index <= max; index++ {
    
15.                 result = result + index * index
    
16.         }
    
17.         return result
    
18. }
    
19. 
    
20. func Problem006(maxNumber int) int {
    
21.     square := SumOfSquareSequence(1, maxNumber)   
    
22.         sequence := SumOfArithmeticSequence(1, maxNumber, 1)
    
23.         return sequence * sequence - square
    
24. }
    
25. 
    
26. func main() {
    
27.         fmt.Println("Problem 006 result: ", Problem006(100))
    
28. }
    

复制代码

ba_du_co

回复 1# icymirror


    lz没有题目005呀

icymirror

回复 2# ba_du_co
有的，但是之前好像都被自动当作重复发帖屏蔽了。

ba_du_co

回复 3# icymirror


能重来一发?
谢谢