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class Solution {
public:
vector<int> searchRange(vector<int>& nums, int target) {
int len, l, r, mid, l_ans = -1, r_ans = -1;
len = nums.size();
l = 0; r = len - 1;
while(l <= r) {
mid = l + (r - l) >> 1;
if(target == nums[mid]) {
int index = mid;
while(-1 < index && index < len && nums[index] == target) {l_ans = index; --index;}
while(-1 < mid && mid < len && nums[mid] == target) {r_ans = mid; ++mid;}
break;
}
else if(nums[mid] < target){
l = mid + 1;
}
else {
r = mid - 1;
}
}
vector<int> ans = {l_ans, r_ans};
return ans;
}
};
class Solution {
public:
vector<int> searchRange(vector<int>& nums, int target) {
if(nums.empty()) return {-1, -1};
int mid, l = 0, r = nums.size();
while(l < r) {
mid = l + r >> 1;
if(nums[mid] >= target) r = mid;
else l = mid + 1;
}
if(l == nums.size() || nums[l] != target) return {-1, -1};
int start = l;
l = 0, r = nums.size(), mid = 0;
while(l < r) {
mid = l + r >> 1;
if(nums[mid] <= target) l = mid + 1;
else r = mid;
}
int end = l - 1;
return {start, end};
}
};
class Solution {
public:
vector<int> searchRange(vector<int>& nums, int target) {
if(nums.empty()) return {-1, -1};
int le = left(nums, target);
if(le == nums.size() || nums[le] != target) return {-1, -1};
int right = left(nums, target, false) - 1;
return {le, right};
}
private:
int left(const vector<int>& nums, const int target, const bool left = true) {
int l = 0, r = nums.size(), mid = 0;
while(l < r) {
mid = l + (r - l) / 2;
if(nums[mid] > target || (left && nums[mid] == target)) {
r = mid;
}
else {
l = mid + 1;
}
}
return l;
}
};
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