diff --git a/problems/0001.两数之和.md b/problems/0001.两数之和.md
index a15e1349..5bedd0a0 100644
--- a/problems/0001.两数之和.md
+++ b/problems/0001.两数之和.md
@@ -263,13 +263,15 @@ php
 ```php
 function twoSum(array $nums, int $target): array
 {
-    for ($i = 0; $i < count($nums);$i++) {
-        // 计算剩下的数
-        $residue = $target - $nums[$i];
-        // 匹配的index，有则返回index， 无则返回false
-        $match_index = array_search($residue, $nums);
-        if ($match_index !== false && $match_index != $i) {
-            return array($i, $match_index);
+    $map = [];
+    foreach($nums as $i => $num) {
+        if (isset($map[$target - $num])) {
+            return [
+                $i,
+                $map[$target - $num]
+            ];
+        } else {
+            $map[$num] = $i;
         }
     }
     return [];