光陰易逝,科研進(jìn)展緩慢∮壹兀恍恍惚惚間蹉跎了多少時(shí)光。
- Two Sum II - Input array is sorted
**思路:又是雙指針問(wèn)題旱爆,前面遇到的鏈表是否循環(huán)舀射,用的是兩個(gè)不同的指針。在min stack問(wèn)題中用的是兩個(gè)不同的堆棧疼鸟。
Two Sum的題目不是第一次遇到了后控。第一次做的時(shí)候,沒(méi)有設(shè)置是遞增序列的條件空镜,當(dāng)時(shí)用的是字典查找浩淘。
class Solution(object):
def twoSum(self, numbers, target):
"""
:type numbers: List[int]
:type target: int
:rtype: List[int]
"""
i = 0
j = len(numbers)-1
while i <= len(numbers) and j >= 0:
if numbers[i] + numbers[j] == target :
return i+1,j+1
if numbers[i] + numbers[j] > target :
j -= 1
if numbers[i] + numbers[j] < target :
i += 1
- Excel Sheet Column Number
**思路:26進(jìn)制的數(shù)。關(guān)鍵是怎么將A-Z對(duì)應(yīng)到1-26吴攒,有沒(méi)有簡(jiǎn)便方法张抄,除了暴力列舉。字母轉(zhuǎn)相應(yīng)的ASCII碼洼怔,但是這哪記得住ord('a') = 97, ord('A') = 65
class Solution(object):
def titleToNumber(self, s):
"""
:type s: str
:rtype: int
"""
sum = 0
for i in s:
tmp = ord(i) - 64
sum = sum*26 +tmp
return sum