【数据结构】数组操作（LowArrayApp.java）

// LowArrayApp.java  
// demonstrates array class with low-level interface
// to run this program: C>java LowArrayAPP
//java数据结构和算法（第二版）拉佛 著  pdf第46页  数组操作

package first;

class LowArray
{
    private long[] a;                 // ref to array a
    
    public LowArray(int size)         // constructor
    { a = new long[size]; }           // create array
    
    public void setElem(int index, long value)      // set value
    { a[index] =  value; }
    
    public long getElem(int index)    // get value
    { return a[index]; }
    
}    // end class LowArray


public class LowArrayAPP 
{
    public static void main(String[] args)
    {
        LowArray arr;                  // reference
        arr = new LowArray(100);       //create LowArray object
        int nElems = 0;                // number of items in array
        int j;                         // loop variable
        
        arr.setElem(0, 77);
        arr.setElem(1, 99);
        arr.setElem(2, 44);
        arr.setElem(3, 55);
        arr.setElem(4, 22);
        arr.setElem(5, 88);
        arr.setElem(6, 11);
        arr.setElem(7, 00);
        arr.setElem(8, 66);
        arr.setElem(9, 33);
        nElems = 10;        // now 10 items in array
    
    // display items
    for (j = 0; j < nElems; j++) 
        System.out.print(arr.getElem(j) + " ");
        System.out.println("");
    
    //search for data item
    int searchKey = 26;
    for(j=0; j < nElems; j++)
        if(arr.getElem(j) == searchKey)
            break;
    if(j == nElems)
        System.out.println("Can't find " + searchKey);
    else
        System.out.println("Found " + searchKey);
    
    //delete value 55
    for(j = 0; j < nElems; j++)
        if (arr.getElem(j) == 55)
            break;
    
    for(int k = j; k < nElems; k++)        // 删掉的数据项后面所有单元逐个前移一位
        arr.setElem(k, arr.getElem(k+1));
    nElems--;
    
    // display items
        for (j = 0; j < nElems; j++) 
            System.out.print(arr.getElem(j) + " ");
            System.out.println("");
    
    } // end main()
} // end class LowArrayAPP 


运行结果：

77 99 44 55 22 88 11 0 66 33 
Can't find 26
77 99 44 22 88 11 0 66 33