把数字1,2,3,·······2n-1,2n分为两组,每组有n个数,设这两组数a1,a2,a3····an;b1,b2,b3,····bn满足:
问题描述：
把数字1,2,3,·······2n-1,2n分为两组,每组有n个数,设这两组数a1,a2,a3····an;b1,b2,b3,····bn满足:
a1bn
试证明:|a1-b1|+|a2-b2|+|a3-b3|······|an-bn|=n^2
要容易理解
答
:|a1-b1|+|a2-b2|+|a3-b3|······|an-bn|=去了之后就是（2n+2n-1+2n-2+.+n+1）-（n+n-1+n-2+.+1）=n+n+.n=n^2