tic;
j = 0;
data = zeros(1, 100);
for i = 5 : 100000
n = 1 + floor(log10(i));
if i == mod(i^2, 10^n)
j = j + 1;
data(j) = i;
end
end
answer = data(1 : j)
toc
tic;
x = 5 : 100000;
y = mod(x.^2, 10.^(1 + floor(log10(x))));
x(x == y) %采用逻辑数组作为索引值,比find函数运算速度更快
toc