650. Keyboard with only two keys
The sum of prime factors
var minSteps = function(n) {
if (n == 1) return 0
let count = 0, res = n
for (let i = 2; i <= res / 2;) {// The initial value of n
if (n % i == 0) {
count += i
n /= i
}
else i++
}
return count == 0 ? res : count
};
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46. The whole arrangement
var permute = function(nums) {
const res = []
const used = {}
function dfs(path) {
if (path.length == nums.length) {
res.push(path.slice())
return
}
for (const num of nums) {
if (used[num]) continue
path.push(num)
used[num] = true
dfs(path)
path.pop()
used[num] = false
}
}
dfs([])
return res
};
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