arrayinsertdeletetest.java

一些JAVA基础性源代码

package exec.day0911;
/**
 * 实现在一个数组指定位置添加元素和删除元素的功能
 * @author Administrator
 *
 */
public class ArrayInsertDeleteTest {
	int arr[] = {10,3,6,2,8,20};
	int count = 6;
	
	public void insert(int pos,int num){
		if(count==arr.length){
			expand();
		}
		for(int i=count;i>pos;i--){
			arr[i] = arr[i-1];
		}
		arr[pos] = num;
		count++;
	}
	public void delete(int pos){
		count--;
		for(int i=pos;i<count;i++){
			arr[i] = arr[i+1];
		}
	}
	public void expand(){
		int arr2[] = new int[arr.length*2];
		System.arraycopy(arr, 0, arr2, 0, arr.length);
		arr = arr2;
	}
	public void print(){
		System.out.print("[");
		for(int i=0;i<count;i++){
			System.out.print(arr[i]+" ");
		}
		System.out.println("]");
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		ArrayInsertDeleteTest t = new ArrayInsertDeleteTest();
		t.print();
		t.insert(2, 100);
		t.print();
		t.insert(4, 200);
		t.print();
		t.delete(5);
		t.print();
	}
}