void combination(int nLED, int nLight, int max, bool zero,

int start, int k, int solution,

vector<vector<string>>& result) {

if (solution > max){

return;

}

if (k == 0) {

char tmp[5] = "";

if (zero) {

sprintf(tmp, "%02d", solution);

}else{

sprintf(tmp, "%d", solution);

}

result[nLight].push_back(tmp);

return;

}

for (int i=start; i<=nLED-k; i++) {

solution += pow(2, i);

combination(nLED, nLight, max, zero, i+1, k-1, solution, result);

solution -= pow(2, i);

}

}

void generate_combination(int nLED, int max, bool zero, vector<vector<string>>& result) {

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

combination(nLED, i, max, zero, 0, i, 0, result);

}

}

void print(vector<vector<string>>& vv) {

for(auto v : vv) {

cout << "[ ";

for (auto i : v) {

cout << i << " ";

}

cout << "]" << endl;

}

}

vector<vector<string>> hour;

vector<vector<string>> mins;

Solution():hour(4, vector<string>()), mins(6, vector<string>()){

generate_combination(4, 11, false, hour);

//print(hour);

//[ 0 ]

//[ 1 2 4 8 ]

//[ 3 5 9 6 10 ]

//[ 7 11 ]

generate_combination(6, 59, true, mins);

//print(mins);

//[ 00 ]

//[ 01 02 04 08 16 32 ]

//[ 03 05 09 17 33 06 10 18 34 12 20 36 24 40 48 ]

//[ 07 11 19 35 13 21 37 25 41 49 14 22 38 26 42 50 28 44 52 56 ]

//[ 15 23 39 27 43 51 29 45 53 57 30 46 54 58 ]

//[ 31 47 55 59 ]

}

vector<string> readBinaryWatch(int num) {

vector<string> result;

for (int i = 0; i <= 3 && i <= num; i++) {

if (num - i > 5) {

continue;

}

for (auto h : hour[i]) {

for (auto m : mins[num - i]) {

result.push_back( h + ":" + m );

}

}

}

return result;

}