[程式演算法] y=1^2+2^2+.....n^2，不能用乘法 只能用一層loop

y=1^2+2^2+.....n^2

y = 1 + 4 + 9 + 16...

1 =  0 + (1 + 0)

5 = 1 + (3 + 1)

14 = 5 + (5 + 4)

30 = 14 + (7+ 9)

var sum = 0

var temp = 1

 var loopvalue = 0;

for (i = 1; i <= n; i++) {

  sum = sum + (temp  + loopvalue );

  loopvalue = (temp  + loopvalue );

  temp = temp + 2;

}