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A binary watch has 4 LEDs on the top which represent the hours (0-11), and the 6 LEDs on the bottom represent the minutes (0-59).

Each LED represents a zero or one, with the least significant bit on the right.

Input: n = 1

Return: ["1:00", "2:00", "4:00", "8:00", "0:01", "0:02", "0:04", "0:08", "0:16", "0:32"]

Note:

The order of output does not matter.

The hour must not contain a leading zero, for example "01:00" is not valid, it should be "1:00".

The minute must be consist of two digits and may contain a leading zero, for example "10:2" is not valid, it should be "10:02".

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class Solution {

public:

vector<string>readBinaryWatch(int num) {

vector<string>re;

for (int i = 0; i <= 11; i++) {

int count =totalOne(i);

if (count <= num) {

for (int j = 0; j <= 59; j++) {

int count2 = totalOne(j);

if (count2 == num - count) {

if (j < 10) {

re.push_back(to_string(i) + ":" + "0"+to_string(j));

}

else {

re.push_back(to_string(i) + ":" + to_string(j));

}

}

}

}

}

return re;

}

int totalOne(int n) {

int count = 0;

while (n > 0) {

if (n % 2 == 1) {

count++;

}

n = n / 2;

}

return count;

}

};