Power representation in go language

1 cause

Rigid contact Go After language , Start using Go Algorithm problem , Want to write a 2 Of 3 Power , Find out C Linguistic 2^3 It's not working

a := 2 ^ 3 

The running result is 1 Not what you want 8

2 reason

It was only after checking that ,Go Symbols in language “ ^ ” No longer used to power , It means “ Bitwise exclusive or operation ”, The specific operation rules are as follows ：

Bitwise XOR （^） : One for 0, One for 1 , The result is 1 , Otherwise 0（ Bits represent binary machine code ）, Examples are as follows ：

2 ^ 3
2  Complement  0000 0010
3  Complement  0000 0011
2 ^ 3   0000 0001 => 1

therefore Go In language 2 ^ 3 = 1 instead of 8（ Be careful ： Computers operate according to complement ）

3 Go To the power of

3.1 In general

Go Language to achieve the calculation of power , We call math.Pow function ,math.Pow(x, y) So we can find out x Of y Power .

With 2 Of 3 Power as an example ：

a := math.Pow(2, 3)

3.2 A special case

When asked 2 Of n In the second place , We can use Go Left shift operator of language << , Realize left shift operation .

The operation rule of shift left is shift left N position , It's times 2 Of N Power . Examples are as follows ：

3.2.1 Move left <<

a := 1 << 3 // 2 Of 3 Power *1

The result is shown in Fig. ：

	b := 1 << 6 // 2 Of 6 Power *1 64
	c := 4 << 2 // 2 Of 2 Power *4 16
	d := 4 << 3 // 2 Of 3 Power *4 32

Since there is a left shift , Then there is a right shift

3.2.2 Move right >>（ expand ）

The operation rule of shift right is shift right N position , Is divided by 2 Of N Power . Example ：

a := 16 >> 3 // 16 Divide 2 Of 3 Power 

Running results ：

3.2.3 principle

stay Golang in , Bit operators are mainly used for binary operations of numeric types .

• Bitwise And The operation rule is , If the binary bits corresponding to both numbers are 1, So the result is 1, Otherwise, the result is 0.
• Bitwise or The operation rule is , If one of the binary bits corresponding to two numbers is 1, So the result is 1, Otherwise, the result is 0.
• Bitwise Exclusive or The operation rule is that if the corresponding binary bits of two numbers are different , So the result is 1, Otherwise, the result is 0.