质数判断程序(仅限4位数)

yangff

a=[]
a[0] = 0
a[1] = 0
for i in 2..99999
a = 0
end
for i in 2..99999
a = 1
b = i*2
while b <=99999
  a = 0
  b += i
end
end
for i in 2..99999
print i.to_s + "是质数" if a == 1
end

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系统信息：本贴获得楼主认可，66RPG感谢您的热情解答～

yangff

for i in 2..99999
print i.to_s + "是质数" if a == 1
end
=》
for i in 2..99999
print i.to_s + "是质数" if a == 1
print i.to_s + "是合数" if a == 0
end


老师说这叫筛法