(1+3+5+7+......+99+101)-(2+4+6+......+98+100)=

= 101-50 =51

这个
51或许吧
见过好多了忘记了

(1+3+5+7+......+99+101)-(2+4+6+......+98+100)
=(1-2)+(3-4)+(5-6)+(7-8)+......+(99-100)+101
=-1-1-1-1......-1+101 [共50个-1]
=-50+101
=51

=[（101+1）x25+1]-[（100+2）x24+2]
=101