接着来看第4个函数，int replaceByte(int x, int n, int c)，看题目给出的例子，replaceByte(0x12345678,1,0xab) = 0x1234ab78。我们可以多写几个例子，进而找出规律，比如： replaceByte(0x12345678,2,0xab) = 0x12ab5678 replaceByte(0x12345678,3,0xab) =