fix: solutions

Author: yanglbme

solution/3400-3499/3450.Maximum Students on a Single Bench/README.md

@@ -156,7 +156,7 @@ public:
         }
         int ans = 0;
         for (const auto& s : d) {
-            ans = max(ans, (int)s.second.size());
+            ans = max(ans, (int) s.second.size());
         }
         return ans;
     }

solution/3400-3499/3450.Maximum Students on a Single Bench/README_EN.md

@@ -154,7 +154,7 @@ public:
         }
         int ans = 0;
         for (const auto& s : d) {
-            ans = max(ans, (int)s.second.size());
+            ans = max(ans, (int) s.second.size());
         }
         return ans;
     }

solution/3400-3499/3450.Maximum Students on a Single Bench/Solution.cpp

@@ -3,11 +3,12 @@ class Solution {
     int maxStudentsOnBench(vector<vector<int>>& students) {
         unordered_map<int, unordered_set<int>> d;
         for (const auto& e : students) {
-            d[e[0]].insert(e[1]);
+            int studentId = e[0], benchId = e[1];
+            d[benchId].insert(studentId);
         }
         int ans = 0;
-        for (auto& [_, s] : d) {
-            ans = max(ans, (int) s.size());
+        for (const auto& s : d) {
+            ans = max(ans, (int) s.second.size());
         }
         return ans;
     }

solution/3400-3499/3450.Maximum Students on a Single Bench/Solution.java

@@ -1,15 +1,14 @@
 class Solution {
-public:
-    int maxStudentsOnBench(vector<vector<int>>& students) {
-        unordered_map<int, unordered_set<int>> d;
-        for (const auto& e : students) {
+    public int maxStudentsOnBench(int[][] students) {
+        Map<Integer, Set<Integer>> d = new HashMap<>();
+        for (var e : students) {
             int studentId = e[0], benchId = e[1];
-            d[benchId].insert(studentId);
+            d.computeIfAbsent(benchId, k -> new HashSet<>()).add(studentId);
         }
         int ans = 0;
-        for (const auto& s : d) {
-            ans = max(ans, (int)s.second.size());
+        for (var s : d.values()) {
+            ans = Math.max(ans, s.size());
         }
         return ans;
     }
-};
+}