題目
The sum of the squares of the first ten natural numbers is,12 + 22 + ... + 102 = 385
The square of the sum of the first ten natural numbers is,(1 + 2 + ... + 10)2 = 552 = 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.
找出前一百個自然數的平方和與和平方的差。
前十個自然數的平方和是:
前十個自然數的和的平方是:
(1 + 2 + ... + 10)2 = 552 = 3025
所以平方和與和的平方的差是3025 - 385 = 2640.
解答:該題數據規模不大,直接計算就可以了。Java程序
public class N_6 {
public static void main(String []args)
{
int n=100;
int number1=0,number2=0;
for(int i=1;i<=n;i++)
{
number1=number1+i*i;
number2=number2+i;
}
number2=number2*number2;
System.out.println(number2-number1);
}
}
運行結果:25164150