using Comparator function ,Sorting, 5 Line code
Best approach for begginer\nWe have to first make a Compartaor Function which sort vector in non increasing order.\n1. We first arrange string with more digit. 
Best approach for begginer\nWe have to first make a Compartaor Function which sort vector in non increasing order.\n1. We first arrange string with more digit. Ex: "123" before "97".\n2. If digits in both string are same then we place greater string first. Ex:- "97" before "87".\n3. We sort the vector according to Point 1 and Point 2. \n4. Now our vector is in non increasing order. so we return K-1 element of vector\nCode   :-\n\'\'\'\nbool compareinterval(string a,string b){\n    if(a.size()==b.size())return a>b;\n     return a.size()>b.size();\n}\nclass Solution {\npublic:\n    string kthLargestNumber(vector<string>& nums, int k) {\n        sort(nums.begin(),nums.end(),compareinterval);\n        return nums[k-1];\n    }\n};\n\'\'\'\nPlease comment if you have any doubt.
['C', 'Sorting', 'C++']