Problem Description
Explanation
To solve this problem, we can simulate the process of providing change to customers. We maintain the count of $5 and $10 bills we have in hand. Whenever a customer pays with $5, we don't need to give any change. If a customer pays with $10, we give back $5 if we have it. If a customer pays with $20, we try to give back a $10 bill and a $5 bill if we have them, or three $5 bills. If at any point we cannot provide the correct change, we return false.
Solutions
class Solution {
public boolean lemonadeChange(int[] bills) {
int count5 = 0, count10 = 0;
for (int bill : bills) {
if (bill == 5) {
count5++;
} else if (bill == 10) {
if (count5 == 0) {
return false;
}
count5--;
count10++;
} else {
if (count10 > 0 && count5 > 0) {
count10--;
count5--;
} else if (count5 >= 3) {
count5 -= 3;
} else {
return false;
}
}
}
return true;
}
}Related LeetCode Problems
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