Question

有人可以解释用虚拟术语将二进制值乘法的Shift Adder方法解释为不理解它，更不用说编写程序来计算答案了。

Answer 1

了解标准的乘法方法

二元移位＆amp;添加和长乘法方法非常相似。

例如在长乘法方法中，如果要将二进制数1001乘以1011，则过程如下：

         1 0 0 0
       x 1 0 1 1
  ---------------
         1 0 0 0  ( Step 1: 1000 x LSB (bit 0) of 1011, which is 1, followed by 0 shift to the left)
+      1 0 0 0 -  ( Step 2: 1000 x bit 1 of 1011, which is again 1, followed by 1 shift to the left)
+    0 0 0 0 - -  ( Step 3: 1000 x bit 2 of 1011, which is 0, followed by 2 shifts to the left)
+  1 0 0 0 - - -  ( Step 4: 1000 x MSB (bit 3) of 1011 which is 1 again, followed by 3 shifts to the left)
 ----------------
   1 0 1 1 0 0 0  ( Step 5: Add all the above)
 ----------------

现在在shift和add方法中，你最后没有添加（步骤5），而是我们不断添加数字，如下所示：

Step 0: Result = 0
Step 1: Result = Result + Step 1 of Long division (1000 x LSB (bit 0) of 1011, which is 1, followed by 0 shift)
               = 0000 + 1000
               = 1000
Step 2: Result = Result + Step 2 of Long division (1000 x bit 1 of 1011, which is again 1, followed by 1 shift)
               = 1000 + 10000 (Additional zero at the end of second term is due to shifting 1000 to the left by 1 time: 1000_0)
               = 11000

Step 3: Result = Result + Step 3 of Long division (1000 x bit 2 of 1011, which is 0, followed by 2 shift)
               = 11000 + 000000
               = 11000
Step 4: Result = Result + Step 4 of Long division (1000 x MSB (bit 3) of 1011 which is 1 again, followed by 3 shift)
               = 11000 + 1000000 (Additional zeros at the end of second term is due to shifting 1000 to the left three times: 1000_000)
               = 1011000

上述算法应该足以让你开始编码我希望。

解释Shift Adder乘法

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