IF-ELSE || EASY  TO UNDERSTAND || JAVA CODE
\nclass Solution {\n\n    public boolean lemonadeChange(int[] bills) {\n        int a = 0, b = 0;\n\n        for (int i = 0; i < bills.length; i++) {\n         
```\nclass Solution {\n\n    public boolean lemonadeChange(int[] bills) {\n        int a = 0, b = 0;\n\n        for (int i = 0; i < bills.length; i++) {\n            if (bills[i] == 5) {\n                a++;\n            }\n            if (bills[i] == 10) {\n                if (a == 0) return false;\n\n                b++;\n\n                a--;\n            }\n            if (bills[i] == 20) {\n                if (a > 0 && b > 0) {\n                    a--;\n                    b--;\n                } else if (a >= 3) {\n                    a -= 3;\n                } else return false;\n            }\n        }\n        return true;\n    }\n}\n```
['Array']