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For example, n = 12 => Previous number power of 2 is 8.

For example, n = 20 => Previous number power of 2 is 16.

**Approach to solve this problem**

**Step 1** − Define a method that accepts a number n.

**Step 2** − Perform n | (n >> k), where k is 1, 2, 4, 8, 16.

**Step 3** − At the end, return n - (n >> 1).

package main import "fmt" func PreviousPowOf2(n int) int{ n = n | (n >> 1) n = n | (n >> 2) n = n | (n >> 4) n = n | (n >> 8) n = n | (n >> 16) return n - (n >> 1) } func main(){ fmt.Printf("Previous round number, power of 2 for %d is %d\n", 20, PreviousPowOf2(20)) fmt.Printf("Previous round number, power of 2 for %d is %d\n", 12, PreviousPowOf2(12)) fmt.Printf("Previous round number, power of 2 for %d is %d\n", 131, PreviousPowOf2(131)) }

Previous round number, power of 2 for 20 is 16 Previous round number, power of 2 for 12 is 8 Previous round number, power of 2 for 131 is 128

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