feat: 实现从输入字符串中提取并排序数字的功能

添加头文件并实现从输入字符串中提取数字字符，按降序排序后输出
跳过前导零以避免无效输出

src/11/6/P14357.cpp

@@ -1,3 +1,32 @@
-int main(){
+#include <algorithm>
+#include <cctype>
+#include <functional>
+#include <iostream>
+#include <istream>
+#include <string>
+#include <vector>
+using ll = int64_t;
 
+std::string s;
+std::vector<char> v;
+
+int main(){
+    std::iostream::sync_with_stdio(false);
+    std::cin.tie(nullptr);
+
+    std::cin>>s;
+    v.reserve(s.size());
+    for(char c:s){
+        if(isdigit(c)){
+            v.emplace_back(c);
+        }
+    }
+    std::sort(v.begin(),v.end(),std::greater<>());
+    bool isf=true;
+    for(char c:v){
+        if(isf&&c=='0')continue;
+        isf=false;
+        std::cout<<c;
+    }
+    std::cout<<"\n";
 }