写一个读入学生成绩 并能确定分数等级的程序（以最高分-10 A，-20 B，-30 C，-40 D划分等级）






代码：【如有更简便或更加好的方法 请高人指点】
import javax.swing.JOptionPane;
public class Demo01 {

    public static void main(String[] args) {
        String numberOfStudentString = JOptionPane.showInputDialog("请输入学生总数：");
        
        int numberOfStudent = Integer.parseInt(numberOfStudentString);
        
        int[]scores = new int[numberOfStudent];
        int best = 0;
        char grade;
        
        for(int i = 0;i < scores.length;i++){
                String scoreString = JOptionPane.showInputDialog("请输入一个分数:");        
               
                scores[i] = Integer.parseInt(scoreString);
               
                if(scores[i] > best)
                    best = scores[i];
        }
        String output="";
        for (int 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 = 'F';
        
        
        output  +=  "学生 "+i+" 号 的分数是："+scores[i]+" 成绩等级是 "+grade+"\n";
        
        }
        
        JOptionPane.showMessageDialog(null,output);
    }

}

求最小元素的下标

用数组{1,2,4,5,10,100,2,-22}测试


代码：【如有更简便或更加好的方法 请高人指点】

 
public class min {
    public static void main(String[] args){
        int test[]={1,2,4,5,10,100,2,-22};
        int min =test[0];
        int index=0;
        for(int i=1;i<test.length;i++){
            if(test[i] < min){
                min = test[i];
                index = i;
            }
        }
        System.out.println(index);
    }
}

用swith 怎么写呢~

选择排序 从小到大排序

测试数组 {2，9，5，4，8，1，6}




public class sort {
    public static void main(String [] args){
        int [] test = {2,9,5,4,8,1,6};
        
        for(int i=1;i<test.length;i++){
            int min = test[0];
            int minIndex = 0;
            
            for(int j = i ;j<test.length;j++){
                if(test[j]<min){
                    min = test[j];
                    minIndex = j;
                }
            }
            
            if(minIndex != i-1){
                test[minIndex] = test[i-1];
                test[i-1] = min;
                System.out.print(test[i-1]+" ");
            }
            
        }
        for(int i=0; i<test.length;i++){
            System.out.print(test[i]);
        }
        
    }
   
   
}

   
   
}


[ 本帖最后由 古博文 于 2009-10-21 11:33 编辑 ]