power.java~23~

提供了常用的JAVA技术的示例

package power;

import javax.swing.UIManager;
import java.awt.*;
import java.io.*;

//计 算 3 的 n 次 幂

public class power {

  //Main method
  public static void main(String[] args) throws IOException {
    InputStreamReader ir;
    BufferedReader in;
    ir=new InputStreamReader(System.in);
    in=new BufferedReader(ir);
    System.out.println("input n is :");
    String s=in.readLine();
    int n=Integer.parseInt(s);
    int pow=1;
    int i;

    for(i=0;i<n;i++)
    {
    pow=3*pow;
    if (pow>=Integer.MAX_VALUE)
       break;
    }
    if (i==n+1)
      System.out.println("result is "+pow);
    else
      System.out.println("result is overflow !");
   }
}