标签：代码 tran format put ack else amp The self
柠檬水??找零问题，有5 10 20三种面值。解法：能用10元找零就不用5块。
At a lemonade stand, each lemonade costs $5.
Customers are standing in a queue to buy from you, and order one at a time (in the order specified by bills).
Each customer will only buy one lemonade and pay with either a $5, $10, or $20 bill. You must provide the correct change to each customer, so that the net transaction is that the customer pays $5.
Note that you don‘t have any change in hand at first.
Return true if and only if you can provide every customer with correct change.
Example 1:
Input: [5,5,5,10,20]
Output: true
Explanation:
From the first 3 customers, we collect three $5 bills in order.
From the fourth customer, we collect a $10 bill and give back a $5.
From the fifth customer, we give a $10 bill and a $5 bill.
Since all customers got correct change, we output true.
Example 2:
Input: [5,5,10]
Output: true
Example 3:
Input: [10,10]
Output: false
Example 4:
Input: [5,5,10,10,20]
Output: false
Explanation:
From the first two customers in order, we collect two $5 bills.
For the next two customers in order, we collect a $10 bill and give back a $5 bill.
For the last customer, we can‘t give change of $15 back because we only have two $10 bills.
Since not every customer received correct change, the answer is false.
class Solution { public: bool lemonadeChange(vector<int>& bills) { int five=0,ten=0; for(int i:bills){ if(i==5){ five++; } else if(i==10){ if(five>=1){ ten++; five--; } else{ return false; } } else if(i==20){ if(ten>=1&&five>=1){ ten--; five--; }else if(five>=3){ five-=3; }else{ return false; } } } return true; } };
python代码
class Solution(object): def lemonadeChange(self, bills): """ :type bills: List[int] :rtype: bool """ five,ten=0,0 for bill in bills: #print "bill: {}".format(bill) if bill==5: five+=1 elif bill==10: if five>=1: five-=1 ten+=1 else: return False elif bill==20: if ten>=1 and five>=1: ten-=1 five-=1 elif five>=3: five-=3 else: return False #print "five: {}, ten: {}".format(five,ten) return True
标签：代码 tran format put ack else amp The self
原文地址：https://www.cnblogs.com/learning-c/p/9281142.html
