/*1、用位操作实现无符号整数的乘法运算,函数原型是unsigned int multiply(unsigned int x, unsigned int y);。例如:(11011)2×(10010)2=((11011)2<<1)+((11011)2<<4)。 （unsigned int 占用4个字节，共32位）*/ #include unsigned int multiply(unsigned int a,unsigned int b) { int c =0,i = 0; for (;i < 32;i ++ ) { if(b&1) // 判断最低位是否为1 { c = c + (a << i );//移i位相加 b>>=1;//b右移1位 } else { b>>=1; } } return c ; } int main () { unsigned int x,y; printf(“Please input x and y value:”); scanf(“%u%u”,&x,&y); printf(“自动实现:%d*%d=%d\n”,x,y,x*y); printf(“函数实现:%d*%d=%d\n”,x,y, multiply(x,y)); return 0; } /*2、对一个32位无符号整数做循环右移,函数原型是unsigned int rotate_right(unsigned int x, int n); 所谓循环右移就是把低位移出去的部分再补到高位上去,例如rotate_right(0xdeadbeef, 8)的值应该是0xefdeadbe。*/ #include unsigned int rotate_right(unsigned int x, int n); int main() { unsigned int x; int n ; printf(“Please input x and n:”); scanf(“%u%d”,&x,&n); printf(“x:%u\n”,rotate_right(x, n)); return 0; } unsigned int rotate_right(unsigned int x, int n) { for (int i = 0;i < n ;i ++)// 循环n位 { if (x&1)//判断最低位是否时1，如果是1就移到最高位，最高位加1 { x = x >> 1; x = x + 0x80000000;//x+=1<<31; } else { x = x >> 1; } } return x; }