go (golang) least significant bit (lsb) / last set bit

lsb.go

// for use with signed numbers, like an int, *not* a uint

func lsb(n int) int { return n & (-n) }

func demo() {
	for i := 0; i < 10; i++ {
		fmt.Printf("i %d as bits %04b lsb %b\n", i, i, lsb(i))
	}
}

/* output:
i 0 as bits 0000 lsb 0
i 1 as bits 0001 lsb 1
i 2 as bits 0010 lsb 10
i 3 as bits 0011 lsb 1
i 4 as bits 0100 lsb 100
i 5 as bits 0101 lsb 1
i 6 as bits 0110 lsb 10
i 7 as bits 0111 lsb 1
i 8 as bits 1000 lsb 1000
i 9 as bits 1001 lsb 1
*/