717. 1-bit and 2-bit Characters(python+cpp)
阿新 • • 發佈:2018-12-15
題目:
We have two special characters. The first character can be represented by one bit 0. The second character can be represented by two bits (10 or 11). Now given a string represented by several bits. Return whether the last character must be a one-bit character or not. The given string will always end with a zero. Example 1:
Input: bits = [1, 0, 0] Output: True Explanation: The only way to decode it is two-bit character and one-bit character. So the last character is one-bit character.
Example 2:
Input: bits = [1,1, 1, 0] Output: False Explanation: The only way to decode it is two-bit character and two-bit character. So the last character is NOT one-bit character.
Note:
1 <= len(bits) <= 1000
.bits[i]
is always0
or1
.
解釋: 若當前bit為1,則下一個不用判斷,可以直接跳過,若最後剩下了1bit,則該bit必定為0,返回true,若list初始長度就為1,則該bit必定為0,返回true。 python程式碼:
class Solution(object):
def isOneBitCharacter(self, bits):
"""
:type bits: List[int]
:rtype: bool
"""
if len(bits)==1:
return True
i=0
while i<len(bits):
if i==len(bits)-1:
return True
if bits[i]==1:
i+=2
else:
i+=1
return False
c++程式碼:
class Solution {
public:
bool isOneBitCharacter(vector<int>& bits) {
if(bits.size()==1)
return true;
int i=0;
while (i<bits.size())
{ if (i==bits.size()-1)
return true;
if (bits[i]==1)
i+=2;
else
i+=1;
}
return false;
}
};
總結: