Update Log2

itsubaki · Apr 19, 2024 · 2704db9 · 2704db9
1 parent 993db57
commit 2704db9
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Showing 2 changed files with 9 additions and 5 deletions.
diff --git a/math/number/log.go b/math/number/log.go
@@ -9,12 +9,12 @@ func Log2(N int) (int, error) {
 		return 0, nil
 	}
 
-	if N%2 != 0 {
-		return -1, fmt.Errorf("N must be a power of 2. N=%v", N)
-	}
-
 	var n int = 1
 	for {
+		if N%2 != 0 {
+			return -1, fmt.Errorf("N must be a power of 2")
+		}
+
 		if N/2 == 1 {
 			break
 		}

diff --git a/math/number/log_test.go b/math/number/log_test.go
@@ -9,11 +9,15 @@ import (
 
 func ExampleLog2() {
 	fmt.Println(number.Log2(8))
+	fmt.Println(number.Log2(32))
 	fmt.Println(number.Log2(15))
+	fmt.Println(number.Log2(20))
 
 	// Output:
 	// 3 <nil>
-	// -1 N must be a power of 2. N=15
+	// 5 <nil>
+	// -1 N must be a power of 2
+	// -1 N must be a power of 2
 }
 
 func TestLog2(t *testing.T) {