使用go求幂的几种方法小结

/*
*  二分幂法 求x^n
 */
// 求整数幂
package main
import (
  "fmt"
  "math"
)
func main() {
  var x float64
  var n int
  fmt.Scanf("%f%d", x, n)
  fmt.Println(powerf(x, n))
  fmt.Println(powerf2(x, n))
  fmt.Println(powerf3(x, n))
  fmt.Println(math.Pow(x, float64(n)))
}
func powerf(x float64, n int) float64 {
  ans := 1.0
  for n != 0 {
    if n%2 == 1 {
      ans *= x
    }
    x *= x
    n /= 2
  }
  return ans
}
/*
*  递归法 求x^n
 */
func powerf2(x float64, n int) float64 {
  if n == 0 {
    return 1
  } else {
    return x * powerf2(x, n-1)
  }
}
/*
*  循环法 求x^n
 */
func powerf3(x float64, n int) float64 {
  ans := 1.0
  for n != 0 {
    ans *= x
    n--
  }
  return ans
}

package main
import "fmt"
func main() {
var a,b = 10,11
fmt.Printf("a+b=%d\n",a+b)
fmt.Printf("a-b=%d\n",a-b)
fmt.Printf("a*b=%d\n",a*b)
fmt.Printf("a/b=%d\n",a/b)
fmt.Printf("a求余b=%d\n",a%b)
var c,d=10,9
println("a>b的结果",c>d)
println("a==b的结果",c==d)
println("ab的结果",cd)
println("a!=b的结果",c!=d)
var e,f = true,false
println(ef)
println(e||f)
println(!f)
var i,j = 1,0
i++
fmt.Println(i)
i--
fmt.Println(i)
j += i // 等价于 j = j+i
fmt.Println(j)
i++
j *= i
fmt.Println(j)
}