Easy and Simple Solution (for beginners)
 # Intuition  \n\n\n\n\n\n\n\n\n\n\n\n\n# Code\n\nclass Solution {\npublic:\n    bool lemonadeChange(vector<int>& nums) {\n        if(nums[0]!=5){\n            
<!-- # Intuition -->\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n<!-- # Approach -->\n<!-- Describe your approach to solving the problem. -->\n\n<!-- # Complexity -->\n<!-- - Time complexity: -->\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n<!-- - Space complexity: -->\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\nclass Solution {\npublic:\n    bool lemonadeChange(vector<int>& nums) {\n        if(nums[0]!=5){\n            return false;\n        }\n        int count_5=0,count_10=0;\n        for(int i=0;i<nums.size();i++){\n            if(nums[i]==5){\n                count_5++;\n            }\n            else if(nums[i]==10){\n                if(count_5>=1){\n                    count_5--;\n                    count_10++;\n                }\n                else{\n                    return false;\n                }\n            }\n            else if(nums[i]==20){\n                if(count_5>=1 && count_10>=1){\n                    count_5--;\n                    count_10--;\n                }\n                else if(count_5>=3){\n                    count_5=count_5-3;\n                }\n                else{\n                    return false;\n                }\n            }\n        }\n        return true;\n    }\n};\n```
['C++']