bits.Sub64() Function in Golang with Examples

The bits.Sub64() Function in Golang is used to find the difference of a, b and borrow, i.e. diff = a – b – borrow.Here the borrow must be 0 or 1; otherwise, the behavior is undefined. To access this function, one needs to imports the math/bits package in the program. The return value of the borrowOutput will be always 0 or 1 in any case.

Syntax:

func Sub64(a, b, borrow uint64) (diff, borrowOut uint64)

Parameters: This function takes three parameters of uint64 type, i.e., a, b, and borrow. The value of borrow parameter is either 1 or 0.

Return Value: This function return two values of uint64 type, i.e., diff and borrowOut. Here diff contains the result of a – b – borrow and borrowOut is either 1 or 0.

Example 1:

// Golang program to illustrate bits.Sub64() Function
package main

import (
    "fmt"
    "math/bits"
)

// Main function
func main() {

    // Finding diff and borrowOu
    // of the specified numbers
    // Using Sub64() function
    nvalue_1, borrowOut := bits.Sub64(11, 5, 0)
    fmt.Println("Diff:", nvalue_1)
    fmt.Println("BorrowOut :", borrowOut)

}

Output:

Diff: 6
BorrowOut : 0

Example 2: Here, you can see that the result is not as excepted as we have taken the value of borrow as 7. So if we are taking borrow input other than 1 and 0 then the behavior will be undefined.

// Golang program to illustrate bits.Sub64() Function
package main

import (
    "fmt"
    "math/bits"
)

// Main function
func main() {

    // Finding diff and borrowOut
    // of the specified numbers
    // Using Sub64() function

    var a, b, borrow uint64 = 12, 87, 7
    Diff, borrowOut := bits.Sub64(a, b, borrow )
    fmt.Println("Number 1:", a)
    fmt.Println("Number 2:", b)
    fmt.Println("Borrow :", borrow )
    fmt.Println("Diff:", Diff)
    fmt.Println("BorrowOut :", borrowOut )

}

Output:

Number 1: 12
Number 2: 87
Borrow : 7
Diff: 18446744073709551540
BorrowOut : 1