旋转数组的二分查找

题目：旋转数组，如{3, 4, 5, 1, 2}是{1, 2, 3, 4, 5}的一个旋转，利用二分查找查找里面的数

这是一道很有意思的题目，容易考虑不周全

#include <iostream>using namespace std;int sequentialSearch(int *array, int size, int destValue){int pos = -1;if (array == NULL || size <= 0)return pos;for (int i = 0; i < size; i++){if (array[i] == destValue){pos = i;break;}}return pos;}int normalBinarySearch(int *array, int leftPos, int rightPos, int destValue){int destPos = -1;if (array == NULL || leftPos < 0 || rightPos < 0){return destPos;}int left = leftPos;int right = rightPos;while (left <= right){int mid = (right - left) / 2 + left;if (array[mid] == destValue){destPos = mid;break;}elseif (array[mid] < destValue){left = mid + 1;}else{right = mid - 1;}}return destPos;}int rotateBinarySearch(int *array, int size, int destValue){int destPos = -1;if (array == NULL || size <= 0){return destPos;}int leftPos = 0;int rightPos = size - 1;while (leftPos <= rightPos){if (array[leftPos] < array[rightPos]){destPos = normalBinarySearch(array, leftPos, rightPos, destValue);break;}int midPos = (rightPos - leftPos) / 2 + leftPos;if (array[leftPos] == array[midPos] && array[midPos] == array[rightPos]){destPos = sequentialSearch(array, size, destValue);break;}if (array[midPos] == destValue){destPos = midPos;break;}if (array[midPos] >= array[leftPos]){if (destValue >= array[leftPos]){destPos = normalBinarySearch(array, leftPos, midPos - 1, destValue);break;} else{leftPos = midPos + 1;}}else{if (array[midPos] <= array[rightPos]){destPos = normalBinarySearch(array, midPos + 1, rightPos, destValue);break;} else{rightPos = midPos - 1;}}}return destPos;}int main(){//int array[] = {3, 4, 5, 1, 2};//int array[] = {1, 2, 3, 4, 5};//int array[] = {1, 0, 1, 1, 1};//int array[] = {1, 1, 1, 0, 1};//int array[] = {1};//int array[] = {1, 2};int array[] = {2, 1};const int size = sizeof array / sizeof *array;for (int i = 0; i <= size; i++){int pos = rotateBinarySearch(array, size, array[i]);cout << "find " << array[i] << " at: " << pos + 1 << endl;}for (int i = size; i >= 0; i--){int pos = rotateBinarySearch(array, size, array[i]);cout << "find " << array[i] << " at: " << pos + 1 << endl;}}