添加 0034.在排序数组中查找元素的第一个和最后一个位置.md C语言解法

problems/0034.在排序数组中查找元素的第一个和最后一个位置.md

@@ -739,6 +739,60 @@ class Solution {
 }
 ```
 
+### C
+```c
+int searchLeftBorder(int *nums, int numsSize, int target) {
+    int left = 0, right = numsSize - 1;
+    // 记录leftBorder没有被赋值的情况
+    int leftBorder = -1;
+    // 边界为[left, right]
+    while (left <= right) {
+        // 更新middle值，等同于middle = (left + right) / 2
+        int middle = left + ((right - left) >> 1);
+        // 若当前middle所指为target，将左边界设为middle，并向左继续寻找左边界
+        if (nums[middle] == target) {
+            leftBorder = middle;
+            right = middle - 1;
+        } else if (nums[middle] > target) {
+            right = middle - 1;
+        } else {
+            left = middle + 1;
+        }
+    }
+    return leftBorder;
+}
+int searchRightBorder(int *nums, int numsSize, int target) {
+    int left = 0, right = numsSize - 1;
+    // 记录rightBorder没有被赋值的情况
+    int rightBorder = -1;
+    while (left <= right) {
+        int middle = left + ((right - left) >> 1);
+        // 若当前middle所指为target，将右边界设为middle，并向右继续寻找右边界
+        if (nums[middle] == target) {
+            rightBorder = middle;
+            left = middle + 1;
+        } else if (nums[middle] > target) {
+            right = middle - 1;
+        } else {
+            left = middle + 1;
+        }
+    }
+    return rightBorder;
+}
+
+int* searchRange(int* nums, int numsSize, int target, int* returnSize){
+    int leftBorder = searchLeftBorder(nums, numsSize, target);
+    int rightBorder = searchRightBorder(nums, numsSize, target);
+
+    // 定义返回数组及数组大小
+    *returnSize = 2;
+    int *resNums = (int*)malloc(sizeof(int) * 2);
+    resNums[0] = leftBorder;
+    resNums[1] = rightBorder;
+    return resNums;
+}
+```
+
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