int a=3，b=4，t；

The values of a and b can be exchanged by the following three statements (this operation is a bit like exchanging the liquid in two bottles with an empty bottle):

t = a； a = b； b = t；

I don't know what "the exchange of values between ABCs" is. If we want to "rotate" A = 1, B = 2 and C = 3 into A = 2, B = 3 and C = 1,

Then use the following statement to achieve:

t = a； a = b； b = c； c = t；

If you want to change three variables of arbitrary size into a sequence from small to large through exchange, you can use the following program segment:

int a，b，c，t；

Scanf("%d %d %d ",& i, & ampb & amp；; c)；

If (a & gtb){ t = a；; a = b； b = t； }

If (a & gtc){ t = a；; a = c； c = t； }

If (b & gtc){ t = b；; b = c； c = t； }

Printf ("The order from small to large is: %d %d %d\n", a, b, c);