Java数据结构与算法（查找）

public class SearchTest {
	public static void main(String[] args) {
		Search s = new Search();
//		int arr[]= {0,2,3,4,12,23,23,23,23,23,23,23,23,23,23,23,23};
//		Set<Integer> resIndexSet=s.binarySearch2(arr, 23, 0, arr.length-1);
//		System.out.println(resIndexSet);
		int arr[] = new int[100];
		for (int i = 0; i < 100; i++) {
			arr[i] = i + 1;
		}
		System.out.println("二分查找" + s.binarySearch(arr, 100, 0, arr.length - 1));
		Set<Integer> resIndexSet1 = s.binarySearch2(arr, 100, 0, arr.length - 1);
		System.out.println("二分查找" + resIndexSet1);
		Set<Integer> resIndexSet2 = s.interpolationSearch(arr, 100, 0, arr.length - 1);
		System.out.println("插值查找" + resIndexSet2);
		System.out.println("黄金分割发查找"+s.fibonacciSearch(arr, 3));
	}
}

class Search {
	// 二分查找
	public int binarySearch(int arr[], int number, int left, int right) {
		if (left > right || arr[left] > number || arr[right] < number) {
			return -1;
		}
		int middle = (left + right) / 2;
		if (arr[middle] > number) {
			return binarySearch(arr, number, left, middle - 1);
		} else if (arr[middle] < number) {
			return binarySearch(arr, number, middle + 1, right);
		} else {
			return middle;
		}
	}

	// 二分查找（如果有重复的就全部输出）
	public Set<Integer> binarySearch2(int arr[], int number, int left, int right) {
		if (left > right || arr[left] > number || arr[right] < number) {
			return new TreeSet<Integer>();
		}
		int middle = (left + right) / 2;
		Set<Integer> resIndexSet = new TreeSet<Integer>();
		if (arr[middle] > number) {
			return binarySearch2(arr, number, left, middle - 1);
		} else if (arr[middle] < number) {
			return binarySearch2(arr, number, middle + 1, right);
		} else {
			int temp = middle - 1;
			while (true) {
				if (arr[temp] != number || temp < 0) {
					break;
				}
				resIndexSet.add(temp);
				temp--;
			}
			resIndexSet.add(middle);
			temp = middle + 1;
			while (true) {
				if (temp > arr.length - 1 || arr[temp] != number) {
					break;
				}
				resIndexSet.add(temp);
				temp++;
			}
			return resIndexSet;
		}
	}

	// 插值查找
	public Set<Integer> interpolationSearch(int arr[], int number, int left, int right) {
		if (left > right || arr[left] > number || arr[right] < number) {
			return new TreeSet<Integer>();
		}
		int middle = left + (number - arr[left]) / (arr[right] - arr[left]) * (right - left);
		Set<Integer> resIndexSet = new TreeSet<Integer>();
		if (arr[middle] > number) {
			return interpolationSearch(arr, number, left, middle - 1);
		} else if (arr[middle] < number) {
			return interpolationSearch(arr, number, middle + 1, right);
		} else {
			int temp = middle - 1;
			while (true) {
				if (arr[temp] != number || temp < 0) {
					break;
				}
				resIndexSet.add(temp);
				temp--;
			}
			resIndexSet.add(middle);
			temp = middle + 1;
			while (true) {
				if (temp > arr.length - 1 || arr[temp] != number) {
					break;
				}
				resIndexSet.add(temp);
				temp++;
			}
			return resIndexSet;
		}
	}

	// 斐波那契查找
	public int fibonacciSearch(int arr[], int key) {
		int low = 0;
		int high = arr.length - 1;
		int k = 0;// 表示斐波那契分割数值的下标
		int mid = 0;
		int f[] = fibonacci();
		while (high > f[k] - 1) {
			k++;
		}
		// 因为f[K]的值可能大于arr的长度，因此我们需要使用Arrays类，构建一个新的数组，并且指向arr[]
		// 不足的地方会使用0填充
		int[] temp = Arrays.copyOf(arr, f[k]);
		for (int i = high + 1; i < temp.length; i++) {
			temp[i] = arr[high];
		}
		while (low <= high) {
			mid = low + f[k - 1] - 1;
			if (key < temp[mid]) {
				high = mid - 1;
				k--;
			} else if (key > temp[mid]) {
				low = mid + 1;
				k -= 2;
			} else {
				if (mid <= high) {
					return mid;
				} else
					return high;
			}
		}
		return -1;
	}

	public int[] fibonacci() {
		int f[] = new int[20];
		f[0] = 1;
		f[1] = 1;
		for (int i = 2; i < 20; i++) {
			f[i] = f[i - 1] + f[i - 2];
		}
		return f;
	}
}