Merge pull request #683 from KingArthur0205/master

添加 0704.二分查找.md C语言版本

problems/0704.二分查找.md

@@ -374,7 +374,7 @@ func search(nums: [Int], target: Int) -> Int {
         } else if target > nums[middle] {
             // 当目标在区间右侧，就需要更新左边的边界值，新区间为[middle + 1, right]
             left = middle + 1
-        } else {
+        } else { 
             // 当目标就是在中间，则返回中间值的下标
             return middle
         }
@@ -450,6 +450,33 @@ impl Solution {
 }
 ```
 
+**C:**
+```c
+int search(int* nums, int numsSize, int target){
+    int left = 0;
+    int right = numsSize-1;
+    int middle = 0;
+    //若left小于等于right，说明区间中元素不为0
+    while(left<=right) {
+        //更新查找下标middle的值
+        middle = (left+right)/2;
+        //此时target可能会在[left,middle-1]区间中
+        if(nums[middle] > target) {
+            right = middle-1;
+        } 
+        //此时target可能会在[middle+1,right]区间中
+        else if(nums[middle] < target) {
+            left = middle+1;
+        } 
+        //当前下标元素等于target值时，返回middle
+        else if(nums[middle] == target){
+            return middle;
+        }
+    }
+    //若未找到target元素，返回-1
+    return -1;
+}
+```
 
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 * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)