tpanel.java

将前缀表达式转为中缀表达式

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 */

package pro;
import java.awt.*;
import javax.swing.*;


/**
 *
 * @author Administrator
 */
public class Tpanel extends JPanel {
    public static String in="";
    public J_Tree root;
    @Override
    protected void paintComponent(Graphics g){
        
        int n,i1,k=0;
        double rmark=228,lmark=50,X=rmark;
        J_Tree p=null,q=null,p1;
        char[] a1;
        g.clearRect(0, 0, 500, 500);
        n=in.length();
        if(n==0){}
        else{
        a1=new char[n];
        a1[0]=in.charAt(0);
        p=new J_Tree(a1[0]); 
        q=p;root=p;
        g.drawOval((int)rmark-10,(int)lmark-10,20,20);
        g.drawString(""+a1[0],(int)rmark-10+8,(int)lmark-10+15);
        for(i1=1;i1<n;i1++){
            a1[i1]=in.charAt(i1);
            if(a1[i1]=='+'||a1[i1]=='-'||a1[i1]=='*'||a1[i1]=='/'||a1[i1]=='^'){
                q=new J_Tree(a1[i1]);
                
                if(p.left==null){
                    p.left=q;
                    q.parent=p;
                    rmark=rmark/2;lmark=lmark+50;X=X-rmark;
                     g.drawLine((int)(X+rmark*10/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(lmark-500/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(X+rmark-rmark*10/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(lmark-50+500/java.lang.Math.sqrt(2500+rmark*rmark)));
                    g.drawOval((int)X-10,(int)lmark-10,20,20);
                    g.drawString(""+a1[i1],(int)X-10+8,(int)lmark-10+15);
                }
                else if(p.right==null){
                    p.right=q;
                    q.parent=p;
                    rmark=rmark/2;lmark=lmark+50;X=X+rmark;
                    g.drawLine((int)(X-rmark*10/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(lmark-500/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(X-rmark+rmark*10/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(lmark-50+500/java.lang.Math.sqrt(2500+rmark*rmark)));
                    g.drawOval((int)(X-10),(int)lmark-10,20,20);
                    g.drawString(""+a1[i1],(int)(X-10+8),(int)lmark-10+15);
                }
                else{
                    while(p.right!=null){
                        p1=p;
                        p=p.parent;
                        if(p1==p.right) X=X-rmark;
                        else X=X+rmark;
                        lmark=lmark-50;
                        rmark=rmark*2;
                    }
                    p.right=q;
                    q.parent=p;
                    rmark=rmark/2;lmark=lmark+50;X=X+rmark;
                    g.drawLine((int)(X-rmark*10/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(lmark-500/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(X-rmark+rmark*10/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(lmark-50+500/java.lang.Math.sqrt(2500+rmark*rmark)));
                    g.drawOval((int)(X-10),(int)lmark-10,20,20);
                    g.drawString(""+a1[i1],(int)(X-10+8),(int)lmark-10+15);
                }
                p=q;
            }
            else{
                q=new J_Tree(a1[i1]);
                if(p.left==null){
                    rmark=rmark/2;lmark=lmark+50;X=X-rmark;if(rmark<8)k=1;
                    g.drawOval((int)X-10,(int)lmark-10,20,20);
                    g.drawString(""+a1[i1],(int)X-10+8,(int)lmark-10+15);
                    g.drawLine((int)(X+rmark*10/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(lmark-500/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(X+rmark-rmark*10/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(lmark-50+500/java.lang.Math.sqrt(2500+rmark*rmark)));
                    p.left=q;
                    X=X+rmark;rmark=rmark*2;lmark=lmark-50;
                    
                }
                else if(p.right==null){
                    rmark=rmark/2;lmark=lmark+50;X=X+rmark;if(rmark<8)k=1;
                    g.drawOval((int)(X-10),(int)lmark-10,20,20);
                    g.drawString(""+a1[i1],(int)(X-10+8),(int)lmark-10+15);
                    p.right=q;
                    g.drawLine((int)(X-rmark*10/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(lmark-500/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(X-rmark+rmark*10/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(lmark-50+500/java.lang.Math.sqrt(2500+rmark*rmark)));
                    X=X-rmark;rmark=rmark*2;lmark=lmark-50;
                    
                }
                else{
                    while(p.right!=null){
                        p1=p;
                        p=p.parent;
                        if(p1==p.right) X=X-rmark;
                        else X=X+rmark;
                        lmark=lmark-50;
                        rmark=rmark*2;
                    }
                    p.right=q;
                    rmark=rmark/2;lmark=lmark+50;X=X+rmark;if(rmark<8)k=1;
                    g.drawOval((int)(X-10),(int)lmark-10,20,20);
                    g.drawString(""+a1[i1],(int)(X-10+8),(int)lmark-10+15);
                    p.right=q;
                    g.drawLine((int)(X-rmark*10/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(lmark-500/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(X-rmark+rmark*10/java.lang.Math.sqrt(2500+rmark*rmark)),
                               (int)(lmark-50+500/java.lang.Math.sqrt(2500+rmark*rmark)));
                    X=X-rmark;rmark=rmark*2;lmark=lmark-50;
                    
                }
                    
            }
        }
        if(k==1){
            g.clearRect(0, 0, 456, 800);
            g.drawString("树的深度大于5，本软件暂不支持", 150, 200);
            
        }
        
        }
        
        
        
       
        
        
    }
    

}