二分查找和快速排序分别是查找和排序算法中最重要的算法。下面代码采用java语言来进行编写。

public class BinarySearch {
	
	
	/**
	 * 折半查找
	 * @param  所要查找的数组， 要查找的关键字
	 * @return 如果找到，则返回元素在数组中的下标，否则返回-1
	 */
	public static int binarySearch(int[] nums, int key){
		
		int low = 0;
		int high = nums.length - 1;
		
		while(low <= high){
			int mid = (low + high) / 2;
			if(nums[mid] == key){
				return mid;
			}else if(nums[mid] > key){
				high = mid - 1;
			}else{
				low = mid + 1;
			}
		}
		return -1;
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int[] nums = {1,2,3,4,5,6,7,8,9};
		int result = binarySearch(nums, 11);
		if(result == -1){
			System.out.println("数组中没有该关键字");
		}else{
			System.out.println("该关键字在数组中的下标为：" + result);
		}
	}

}

public class QuickSort {
	
	public static void quickSort(int[] nums, int low, int high){
		
		if(low < high){
			int i = low;
			int j = high;
			int pivot = nums[i];
			while(i <j){
				while(i <j && nums[j] >= pivot){
					j--;
				}
				if(i <j){
					nums[i] = nums[j];
					i++;
				}
				while(i <j && nums[i] <= pivot){
					i++;
				}
				if(i <j){
					nums[j] = nums[i];
					j--;
				}
			}
			nums[i] = pivot;
			quickSort(nums, low, i -1);
			quickSort(nums, i + 1, high);
		}
	}
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int[] nums = {49,38,65,97,76,13,27,49};
		quickSort(nums, 0, 7);
		for(int i = 0; i<nums.length; i++){
			System.out.print(nums[i]+" ");
		}
	}
}