编程问题

Question

public class tongjifenshu {
public static void main(String[] s)
{
int numberstudents=0;
int[] scores;
                              int i=0;
                             int best=0;
char grade='0';
String numberstudentsString=JOptionPane.showInputDialog(null,"Please enter number of students:","软件班                      级",JOptionPane.QUESTION_MESSAGE);
    numberstudents=Integer.parseInt(numberstudentsString);
scores=new int[numberstudents];
for( i=0;i<scores.length;i++)
{ String scoreString=JOptionPane.showInputDialog(null,"Please enter a score","软件班级",JOptionPane.QUESTION_MESSAGE);
scores[i]=Integer.parseInt(scoreString);
if(scores[i]>best)
best=scores[i];
}
                          String output=" ";
                         
for( i=0;i<scores.length;i++)
{        
                            if(scores[i]>=best-10)
        grade='A';
                                                          
                             else if(scores[i]>=best-20)
       grade='B';
                                                         
                             else if(scores[i]>=best-30)
        grade='C'
                                                          
                              else if(scores[i]>=best-40)
        grade='D';
                              else
        grade='E';     
                                                    
                              
                                          output +="Studets  "+i+"  score is   "+scores[i]+"  and grade is   "+grade+  "\n";
                                         
                                          
                      }
                        
JOptionPane.showMessageDialog(null,output,"软件班级",JOptionPane.INFORMATION_MESSAGE);
  }
}
统计分数后我像分别计数分每个grade的个数。例如：‘A’有几个~~~~~~~~~。在另一个方框中输出。                          
 

Answer 1

import javax.swing.JOptionPane;public class Tangjifengshu {
public static void main(String[] s)
{
int numberstudents=0;
int[] scores;
    int i=0;
    int best=0;
char grade='0';
String numberstudentsString=JOptionPane.showInputDialog(null,
"Please enter number of students:","软件班级",
JOptionPane.QUESTION_MESSAGE);
numberstudents=Integer.parseInt(numberstudentsString);
scores=new int[numberstudents];
for( i=0;i <scores.length;i++)
{ 
String scoreString=JOptionPane.showInputDialog(null,"Please enter a score","软件班级",JOptionPane.QUESTION_MESSAGE);
scores[i]=Integer.parseInt(scoreString);
if(scores[i]>best)
best=scores[i];
}

String output=" ";
int []count;
count =new int[5];
                         
for( i=0;i <scores.length;i++)
{        
        if(scores[i]>=best-10){
         grade='A';
         count[0]++;
        }                                                           
        else if(scores[i]>=best-20){
            grade='B';
            count[1]++;
        }                                              
        else if(scores[i]>=best-30){
         grade='C';
         count[2]++;
        }                                                
        else if(scores[i]>=best-40){
         grade='D';
         count[3]++;
        }
        else{
         grade='E';
         count[4]++;
         }                     
        output +="Studets  "+(i+1)+"  score is   "+scores[i]+"  and grade is   "+grade+  "\n";
                                 
                                         
 }
char c='A';
for (int j = 0; j < count.length; j++) {
output+="\n"+(c++)+":  "+count[j];
}
JOptionPane.showMessageDialog(null,output,"软件班级",
JOptionPane.INFORMATION_MESSAGE);

  }
}

Answer 2

你就直接声明5个变量a b c d e,然后在for循环里面记数啊  比如:
for( i=0;i <scores.length;i++) 
{         
                            if(scores[i]>=best-10) 
        grade='A'; 
        a++;
                                                           
                             else if(scores[i]>=best-20) 
       grade='B'; 
        b++;                                                   
                             else if(scores[i]>=best-30) 
        grade='C' 
         c++;                                                   
                              else if(scores[i]>=best-40) 
        grade='D'; 
          d++;                     else 
        grade='E';      
           e++;                                           
                               
                                          output +="Studets  "+i+"  score is   "+scores[i]+"  and grade is   "+grade+  "\n"; 
                                          
                                           
                      }

Answer 3

加个count[]数组，把统计的个数存入数组就行了其实你的这个程序还有可改进的地方，比如,可一次性输入任意个成绩，成绩之间用空格隔开。代码如下：
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import javax.swing.JOptionPane;public class Tangjifengshu2 {
public static void main(String[] s) throws IOException
{
    int i=0;
    int best=0;
char grade='0';
System.out.println("Pls input your scores around spaces:");
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
String st=(String) br.readLine();
System.out.println(st);

String []result=st.split("\\s+"); //将字符串中的数字字符转化为整数
int []scores=new int[result.length]; 

for( i=0;i <scores.length;i++)
{ 
scores[i]=Integer.parseInt(result[i]); //将转化成的整数存入数组中
if(scores[i]>best)
best=scores[i];
}

String output=" ";
int []count;
count =new int[5];
                         
for( i=0;i <scores.length;i++)
{        
        if(scores[i]>=best-10){
         grade='A';
         count[0]++;
        }                                                           
        else if(scores[i]>=best-20){
            grade='B';
            count[1]++;
        }                                              
        else if(scores[i]>=best-30){
         grade='C';
         count[2]++;
        }                                                
        else if(scores[i]>=best-40){
         grade='D';
         count[3]++;
        }
        else{
         grade='E';
         count[4]++;
         }                     
        output +="Studets  "+(i+1)+"  score is   "+scores[i]+"  and grade is   "+grade+  "\n";
                                 
                                         
 }
char c='A';
for (int j = 0; j < count.length; j++) {
output+="\n"+(c++)+":  "+count[j];
}
JOptionPane.showMessageDialog(null,output,"软件班级",
JOptionPane.INFORMATION_MESSAGE);

  }
}

Answer 4

第13行System.out.println(st);纯属多余，仅作测试程序使用