添加0704二分查找PHP版本

problems/0704.二分查找.md

@@ -478,6 +478,38 @@ int search(int* nums, int numsSize, int target){
 }
 ```
 
+**PHP:**
+```php
+// 左闭右闭区间
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @param Integer $target
+     * @return Integer
+     */
+    function search($nums, $target) {
+        if (count($nums) == 0) {
+            return -1;
+        }
+        $left = 0;
+        $right = count($nums) - 1;
+        while ($left <= $right) {
+            $mid = floor(($left + $right) / 2);
+            if ($nums[$mid] == $target) {
+                return $mid;
+            }
+            if ($nums[$mid] > $target) {
+                $right = $mid - 1;
+            }
+            else {
+                $left = $mid + 1;
+            }
+        }
+        return -1;
+    }
+}
+```
+
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