查找算法大集合

1.顺序查找

int sequnceSearch(const int* array, const int length, const int findValue) {
	if (NULL == array || 0 >= length) {
		return -1;
	}

	for (int i = 0; i < length; ++i) {
		if (findValue == array[i]) {
			return i;
		}
	}

	return -1;
}

2.折半查找

int binarySearch(const int* array, const int length, const int findValue) {
	if (NULL == array || 0 >= length) {
		return -1;
	}

	int left = 0, right = length - 1;
	int middle = (left + right) / 2;
	while (left <= right) {
		middle = (left + right) / 2;

		if (findValue > array[middle]) {
			left = middle + 1;
		} else if (findValue < array[middle]) {
			right = middle - 1;
		} else {
			return middle;
		}
	}

	return -1;
}

3.插值查找

int insertSearch(const int* array, const int length, const int findValue) {
	if (NULL == array || 0 >= length) {
		return -1;
	}

	int left = 0, right = length - 1, middle = 0;
	while (left < right) {
		middle = left
				+ (findValue - array[left]) / (array[right] - array[left])
						* (right - left);//避免分母为0的情况

		if (findValue > array[middle]) {
			left = middle + 1;
		} else if (findValue < array[middle]) {
			right = middle - 1;
		} else {
			return middle;
		}
	}

	return findValue == array[left] ? left : -1;
}

4.Fibonacci查找

int fibonacci(int* array, const int length, const int findValue) {
	if (NULL == array || 0 >= length) {
		return -1;
	}

	int k = 0, fibLength = length;
	int* fib = new int[fibLength];
	fibonacci(fib, fibLength);

	while (length > fib[k] - 1) {
		++k;
	}

	int left = 0, right = length - 1;
	int middle = 0;

	for (int i = length; i < fibLength; ++i) {
		array[i] = fib[right] - 1;
	}

	while (left <= right) {
		middle = left + fib[k] - 1;

		if (findValue > array[middle]) {
			k = k - 1;
			left = middle + 1;
		} else if (findValue < array[middle]) {
			k = k - 2;
			right = middle - 1;
		} else {
			return middle;
		}
	}

	return -1;
}

测试代码

#include<iostream>
using namespace std;

void createSearchArray(int* array, const int length) {
	if (0 >= length) {
		return;
	}

	cout << "请输入" << length << "个元素：" << endl;

	for (int i = 0; i < length; ++i) {
		cout << i << '\t';
		cin >> array[i];
	}
}

void printSearchArray(const int* array, const int length) {
	if (NULL == array || 0 >= length) {
		return;
	}

	for (int i = 0; i < length - 1; ++i) {
		cout << array[i] << '\t';
	}
	cout << array[length - 1] << endl;
}

int main() {
	int length = 0;
	cout << "输入数据的长度：" << endl;
	while (cin >> length) {
		int* x = new int[length];
		int findValue = 0;
		createSearchArray(x, length);
		printSearchArray(x, length);

		for (int i = 0; i < length; ++i) {
			findValue = x[i];

			cout << "findValue:" << findValue << endl;

			cout << "顺序查找的结果:" << sequnceSearch(x, length, findValue) << endl;
			cout << "折半查找的结果:" << binarySearch(x, length, findValue) << endl;
			cout << "插值查找的结果:" << insertSearch(x, length, findValue) << endl;
			cout << "Fibonacci查找的结果:" << insertSearch(x, length, findValue)
					<< endl;
		}

		cout << endl;
		cout << "输入数据的长度：" << endl;
	}

	return 0;
}