修正 0001.两数之和 php版本实现

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++) {
+    $map = [];
-        // 计算剩下的数
+    foreach($nums as $i => $num) {
-        $residue = $target - $nums[$i];
+        if (isset($map[$target - $num])) {
-        // 匹配的index，有则返回index， 无则返回false
+            return [
-        $match_index = array_search($residue, $nums);
+                $i,
-        if ($match_index !== false && $match_index != $i) {
+                $map[$target - $num]
-            return array($i, $match_index);
+            ];
+        } else {
+            $map[$num] = $i;
         }
     }
     return [];