A1留空
A2=ROUNDUP(RAND()*2*(350-SUM($A$1:A1))/(331-ROW(A1)),2)
下拉至A330
A331=350-SUM(A2:A330)
20个随机整数加起来等于1000
=ROUNDUP(RAND()*2*(1000-SUM($A$1:A1))/(21-ROW(A1)),0)
=1000-SUM(A2:A20)
20个随机整数加起来等于500 而且随机数大于10
=RANDBETWEEN(10,(500-SUM($A$1:A1))/(21-ROW(A1)))