빠른 정렬 및 2분 조회 테스트

2249 단어 J#
package wuliao;

import java.util.Random;

public class SearchTest {

	
	public static void main(String[] args) {
		SearchTest test = new SearchTest();
		test.search();
	}
	public void search() {
		int key = 0;
		int[] data = new int[10000000];
		Random r = new Random();
		for (int i = 0; i < data.length; i++) {
			data[i] = r.nextInt(data.length * 2);
			if(i == data.length /3){
				key = data[i];
			}
		}

		//System.out.println(ArrayUtils.toString(data, ""));
		long s = System.currentTimeMillis();
		quickSort(data,0,data.length-1);
		System.out.println("    :  :"+data.length + ";  :"+(System.currentTimeMillis() - s));
		//System.out.println(ArrayUtils.toString(data, ""));
		
		s = System.currentTimeMillis();
		int rt = binarySearch(data,key);
		System.out.println("    :  :"+(System.currentTimeMillis() - s)+ (rt != -1?"ms ;find key index : " + rt:"have not exist"));
		
	}

	
	public int binarySearch(int[] data,int key){
		int start = 0;
		int end = data.length-1;
		while(true){
			int mid = (start + end)/2;
			if(data[mid] > key){
				start = 0;
				end = mid;
			}else if(data[mid] < key){
				start = mid+1;
			}else{
				return mid;
			}
			if(start >= end){
				return -1;
			}
		}		
	}
	
	
	
	public void quickSort(int[] data, int left, int right) {
		if(left >= right) 
			return; 
		
		int index = (left + right) / 2;
		int mid = data[index];
		int i = left-1, j = right+1;

		while (true) {
			while (data[++i] < mid);
			while (data[--j] > mid);
			if(i >= j){
				break;
			}
			swap(data, i, j);
		}
		quickSort(data,left,i-1);
		quickSort(data,j+1,right);
	}

	
	public void swap(int[] data, int i, int j) {
		int t = data[i];
		data[i] = data[j];
		data[j] = t;
	}
	
	

}

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