// Source : https://leetcode.com/problems/binary-watch/

// Author : Han Zichi

// Date : 2016-09-18

/**

* @param {number} num

* @return {string[]}

*/

var readBinaryWatch = function(num) {

let hours = [1, 2, 4, 8];

let minutes = [1, 2, 4, 8, 16, 32];

let ans = [];

dfs(num, 0, 0, 0, 0);

function dfs(left, a, b, hoursTotal, minutesTotal) {

if (hoursTotal >= 12 || minutesTotal >= 60)

return;

if (left === 0) {

let str = hoursTotal + ":";

str += minutesTotal < 10 ? '0' + minutesTotal : minutesTotal;

ans.push(str);

return;

}

// add i to hour

for (let i = a; i < 4; i++) {

dfs(left - 1, i + 1, b, hoursTotal + hours[i], minutesTotal);

}

// add i to minute

for (let i = b; i < 6; i++) {

dfs(left - 1, a, i + 1, hoursTotal, minutesTotal + minutes[i]);

}

}

return Array.from(new Set(ans));

};