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Diffstat (limited to 'other/single_element_sorted_arr.cpp')
-rw-r--r-- | other/single_element_sorted_arr.cpp | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/other/single_element_sorted_arr.cpp b/other/single_element_sorted_arr.cpp new file mode 100644 index 0000000..e9bd894 --- /dev/null +++ b/other/single_element_sorted_arr.cpp @@ -0,0 +1,33 @@ +// 540. Single Element in a Sorted Array +#include "leetcode.h" + +/* + * given a sorted array consisting of only integers where very element appears + * exactly twice, except for one element which appears exactly once. return the + * single element that appears only once. solution func must be o(ln) time and + * o(1) space complexity. + */ + +class Solution { +public: + int singleNonDuplicate(vector<int> &nums) { + int low = 0, high = nums.size() - 1, mid; + while (low < high) { + mid = (low + high) / 2; + if ((mid % 2 && nums[mid - 1] == nums[mid]) || + (!(mid % 2) && nums[mid] == nums[mid + 1])) + low = mid + 1; + else + high = mid; + } + return nums[low]; + } +}; + +int main() { + Solution obj; + vector<int> nums1 = {1, 1, 2, 3, 3, 4, 4, 8, 8}, + nums2 = {3, 3, 7, 7, 10, 11, 11}; + cout << obj.singleNonDuplicate(nums1) << endl; // expect: 2 + cout << obj.singleNonDuplicate(nums2) << endl; // expect: 10 +} |