更新cpp提交，只提交Solution类

Author: luchenqun

.gitignore

@@ -39,4 +39,5 @@ jspm_packages
 tmp/
 *.swp
 .DS_Store
-package-lock.json
+package-lock.json
+.vscode/

lib/commands/show.js

@@ -126,9 +126,8 @@ using namespace std;
 
 int main()
 {
-    Solution *s = new Solution();
+    Solution s;
 
-    delete s;
     return 0;
 }
         `

lib/plugins/leetcode.js

@@ -183,6 +183,14 @@ function runCode(opts, problem, cb) {
     typed_code:  h.getFileData(problem.file)
   });
 
+  if(opts.body.lang === 'cpp') {
+    var start = opts.body.typed_code.indexOf('class Solution');
+    var end = opts.body.typed_code.indexOf('int main()');
+    if(start > 0 && end > 0) {
+      opts.body.typed_code = opts.body.typed_code.substring(start, end);
+    }
+  }
+
   const spin = h.spin('Sending code to judge');
   request(opts, function(e, resp, body) {
     spin.stop();