[leetcode]Search for a Range

public class Solution {
public int[] searchRange(int[] A, int target) {
// Start typing your Java solution below
// DO NOT write main() function
int pos = searchTarget(A, target, 0, A.length -1);
if (pos == -1) return new int[]{-1,-1};

int start = 0;
int end = A.length - 1;
for (int i = pos - 1; i >= 0; i--) {
if (A[i] != target) {
start = i+1;
break;
}
}
for (int i = pos + 1; i < A.length; i++) {
if (A[i] != target) {
end = i - 1;
break;
}
}
return new int[]{start,end};
}

public int searchTarget(int[] A, int target, int left, int right) {
if (left > right) return -1;
int mid = (left + right) / 2;
if (A[mid] == target) return mid;
if (A[mid] > target) return searchTarget(A, target, left, mid -1);
else return searchTarget(A, target, mid+1, right);
}
}

class Solution {
public:
vector<int> searchRange(int A[], int n, int target) {
vector<int> range(2, -1);
int lower = 0;
int upper = n;
int mid;

// Search for lower bound
while (lower < upper) {
mid = (lower + upper) / 2;
if (A[mid] < target)
lower = mid + 1;
else
upper = mid;
}

// If the target is not found, return (-1, -1)
if (A[lower] != target)
return range;
range[0] = lower;

// Search for upper bound
upper = n;
while (lower < upper) {
mid = (lower + upper) / 2;
if (A[mid] > target)
upper = mid;
else
lower = mid + 1;
}
range[1] = upper - 1;

return range;
}
};