trivial: use ++/-- operators instead of += 1, -= 1
trivial: use ++/-- operators instead of += 1, -= 1

jnishi/chainer,okuta/chainer,keisuke-umezawa/chainer,wkentaro/chainer,keisuke-umezawa/chainer,jnishi/chainer,wkentaro/chainer,ktnyt/chainer,wkentaro/chainer,pfnet/chainer,hvy/chainer,niboshi/chainer,chainer/chainer,ktnyt/chainer,ktnyt/chainer,okuta/chainer,ktnyt/chainer,okuta/chainer,wkentaro/chainer,chainer/chainer,hvy/chainer,jnishi/chainer,keisuke-umezawa/chainer,hvy/chainer,keisuke-umezawa/chainer,tkerola/chainer,okuta/chainer,chainer/chainer,hvy/chainer,jnishi/chainer,niboshi/chainer,niboshi/chainer,chainer/chainer,niboshi/chainer