Java程序来计算数字的幂

给定一个数N和一个幂P，任务是找到这个数的指数提高到给定的幂，即N ^P。

例子：

Input: N = 5, P = 2
Output: 25

Input: N = 2, P = 5
Output: 32

以下是找到N ^P的各种方法：

• 方法1：使用递归

  // Java program to find the power of a number
  // using Recursion
    
  class GFG {
    
      // Function to calculate N raised to the power P
      static int power(int N, int P)
      {
          if (P == 0)
              return 1;
          else
              return N * power(N, P - 1);
      }
    
      // Driver code
      public static void main(String[] args)
      {
          int N = 2;
          int P = 3;
    
          System.out.println(power(N, P));
      }
  }
  

  输出：

  8
  

• 方法2：在循环的帮助下

  // Java program to find the power of a number
  // with the help of loop
    
  class GFG {
    
      // Function to calculate N raised to the power P
      static int power(int N, int P)
      {
          int pow = 1;
          for (int i = 1; i <= P; i++)
              pow *= N;
          return pow;
      }
    
      // Driver code
      public static void main(String[] args)
      {
          int N = 2;
          int P = 3;
    
          System.out.println(power(N, P));
      }
  }
  

  输出：

  8
  

• 方法3：使用Math.pow()方法

  // Java program to find the power of a number
  // using Math.pow() method
    
  import java.lang.Math;
    
  class GFG {
    
      // Function to calculate N raised to the power P
      static double power(int N, int P)
      {
          return Math.pow(N, P);
      }
    
      // Driver code
      public static void main(String[] args)
      {
          int N = 2;
          int P = 3;
    
          System.out.println(power(N, P));
      }
  }
  

  输出：

  8.0