/**
* @param {number} num
* @return {string[]}
*/
const count1 = function (n) {
let res = 0
while (n !== 0) {
n = n & (n - 1)
res++
}
return res
}
var readBinaryWatch = function (num) {
let res = []
for (let i = 0; i < 12; i++) {
for (let j = 0; j < 60; j++) {
if (count1(i) + count1(j) === num) {
res.push(i.toString() + ":" + (j < 10 ? "0" + j.toString() : j.toString()))
}
}
}
return res
};
Runtime: 56 ms, faster than 66.18% of JavaScript online submissions for Binary Watch.
Memory Usage: 34.3 MB, less than 100.00% of JavaScript online submissions for Binary Watch.
其中的count1()是用来计算二进制中1的个数
n&(n-1)能清除二进制最低位的1
func count1(n int) int {
var res int
for n != 0 {
n = n & (n - 1)
res++
}
return res
}
func readBinaryWatch(num int) []string {
var res []string
for i := 0; i < 12; i++ {
for j := 0; j < 60; j++ {
if count1(i)+count1(j) == num {
min := strconv.Itoa(j)
if j < 10 {
min = "0" + min
}
fmt.Println("min", min)
result := strconv.Itoa(i) + ":" + min
res = append(res, result)
}
}
}
return res
}
Runtime: 0 ms, faster than 100.00% of Go online submissions for Binary Watch.
Memory Usage: 2.9 MB, less than 100.00% of Go online submissions for Binary Watch.
用过从int转string，总是忘记用这个函数😂😂，然后就会转出一堆乱码。。
class Solution:
def count1(self, n: int) -> int:
res = 0
while n != 0:
n &= n - 1
res += 1
return res
def readBinaryWatch(self, num: int) -> List[str]:
res = []
for i in range(12):
for j in range(60):
if Solution.count1(self, i) + Solution.count1(self, j) == num:
res.append(str(i) + ":" + (("0" + str(j)) if j < 10 else str(j)))
return res
Runtime: 44 ms, faster than 24.96% of Python3 online submissions for Binary Watch.
Memory Usage: 13.8 MB, less than 9.09% of Python3 online submissions for Binary Watch.
class Solution:
def readBinaryWatch(self, num: int) -> List[str]:
hour = [1, 2, 4, 8]
minute = [1, 2, 4, 8, 16, 32]
h_len, m_len = len(hour), len(minute)
res = []
def time(combination, led, start):
if led == 0:
if combination[1] < 10:
res.append(str(combination[0]) + ':0' + str(combination[1]))
else:
res.append(str(combination[0]) + ':' + str(combination[1]))
else:
for i in range(start, h_len + m_len):
if i < h_len:
combination[0] += hour[i]
if combination[0] < 12:
time(combination, led - 1, i + 1)
combination[0] -= hour[i]
else:
combination[1] += minute[i - h_len]
if combination[1] < 60:
time(combination, led - 1, i + 1)
combination[1] -= minute[i - h_len]
cur = [0] * 2
time(cur, num, 0)
return res
Runtime: 40 ms, faster than 56.81% of Python3 online submissions for Binary Watch.
Memory Usage: 14 MB, less than 9.09% of Python3 online submissions for Binary Watch.
暴力美学
作者：SherryOKOK 链接：https: // leetcode - cn.com / problems / binary - watch / solution / cheng - xu - yuan - de - bao - li - mei - xue - by - sherryokok /
简单题解决不花里胡哨😂笑死了
class Solution:
def readBinaryWatch(self, num: int) -> List[str]:
if num < 0 or num > 10:
return None
res = []
for i in range(num + 1):
j = num - i
if i > 3 or j > 5:
continue
hour = self.hours(i)
minute = self.minutes(j)
for a in hour:
for b in minute:
res.append(a + ':' + b)
return res
def hours(self, num):
if num == 0:
res = ['0']
elif num == 1:
res = ['1', '2', '4', '8']
elif num == 2:
res = ['3', '5', '9', '6', '10']
elif num == 3:
res = ['7', '11']
return res
def minutes(self, num):
if num == 0:
res = ['00']
elif num == 1:
res = ['01', '02', '04', '08', '16', '32']
elif num == 2:
res = ['03', '05', '09', '17', '33', '06', '10', '18', '34', '12', '20', '36', '24', '40', '48']
elif num == 3:
res = ['07', '11', '19', '35', '13', '21', '37', '25', '41', '49', '14', '22', '38', '26', '42', '50', '28', '44', '52', '56']
elif num == 4:
res = ['58', '54', '46', '30', '57', '53', '45', '29', '51', '43', '27', '39', '23', '15']
elif num == 5:
res = ['59', '55', '47', '31']
return res
Runtime: 40 ms, faster than 56.81% of Python3 online submissions for Binary Watch.
Memory Usage: 13.7 MB, less than 9.09% of Python3 online submissions for Binary Watch.
