power.java~19~

提供了常用的JAVA技术的示例

package power;

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

//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;

    for(int i=0;i<n;i++)
    {
    pow=3*pow;
    //if (pow>=Integer.MAX_VALUE)
      //  break;

    }
    if (pow>=Integer.MAX_VALUE || pow<=Integer.MIN_VALUE)
      {System.out.println("result is overflow !");}

    else
{       System.out.println("result is "+pow);
        System.out.println(Integer.MIN_VALUE);
        System.out.println(Integer.MAX_VALUE);
}

   }
}