LeetCode: Search for a Range

一次过

class Solution {
public:
    vector<int> searchRange(int A[], int n, int target) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int left = 0;
        int right = n-1;
        while (left <= right) {
            int mid = (left+right)/2;
            if (target == A[mid]) {
                int l, r;
                l = r = 0;
                while (A[mid] == A[mid-l]) l++;
                while (A[mid] == A[mid+r]) r++;
                vector<int> ret;
                ret.push_back(mid-l+1);
                ret.push_back(mid+r-1);
                return ret;
            }
            if (target > A[mid]) left = mid+1;
            else right = mid-1;
        }
        return {-1, -1};
    }
};

 C#

public class Solution {
    public int[] SearchRange(int[] nums, int target) {
        int left = 0;
        int right = nums.Length - 1;
        int[] ans = new int[2];
        while (left <= right) {
            int mid = (left + right) / 2;
            if (target == nums[mid]) {
                int l = 0, r = 0;
                while (mid - l >= 0 && nums[mid] == nums[mid-l]) l++;
                while (mid + r < nums.Length && nums[mid] == nums[mid+r]) r++;
                ans[0] = mid - l + 1;
                ans[1] = mid + r - 1;
                return ans;
            }
            if (target > nums[mid]) left = mid + 1;
            else right = mid - 1;
        }
        ans[0] = ans[1] = -1;
        return ans;
    }
}