"Search for a Range"

Author: lennylxx

README.md

@@ -254,7 +254,7 @@ The `☢` means that you need to have a LeetCode Premium Subscription.
 | 37  | [Sudoku Solver]                                              |                    |
 | 36  | [Valid Sudoku]                                               | [C](src/36.c)      |
 | 35  | [Search Insert Position]                                     | [C](src/35.c)      |
-| 34  | [Search for a Range]                                         |                    |
+| 34  | [Search for a Range]                                         | [C++](src/34.cpp)  |
 | 33  | [Search in Rotated Sorted Array]                             | [C](src/33.c)      |
 | 32  | [Longest Valid Parentheses]                                  |                    |
 | 31  | [Next Permutation]                                           |                    |

src/34.cpp

@@ -0,0 +1,58 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+class Solution {
+public:
+    vector<int> searchRange(vector<int>& nums, int target) {
+        vector<int> ans(2);
+        int n = nums.size();
+        int low = 0;
+        int high = n - 1;
+        int mid;
+        bool found = false;
+        while (low <= high) {
+            mid = low + (high - low) / 2;
+            if (nums[mid] == target) {
+                found = true;
+                break;
+            }
+            else if (nums[mid] < target) {
+                low = mid + 1;
+            }
+            else {
+                high = mid - 1;
+            }
+        }
+
+        if (found) {
+            low = high = mid;
+            while (low >= 0 && nums[low] == target) low--;
+            while (high <= n - 1 && nums[high] == target) high++;
+
+            ans[0] = low + 1;
+            ans[1] = high - 1;
+        }
+        else {
+            ans[0] = ans[1] = -1;
+        }
+
+        return ans;
+    }
+};
+
+int main () {
+    vector<int> nums = {5, 7, 7, 8, 8, 10};
+    int target = 8;
+    Solution s;
+
+    vector<int> ans = s.searchRange(nums, target);
+
+    for (int i = 0; i < ans.size(); i++) {
+        printf("%d ", ans[i]);
+    }
+    printf("\n");
+
+    return 0;
+}