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DFS
Classic example:
full array
Leetour 46: Full Arrangement
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Diagram
* 力扣46：全排列
* @param {
*} nums
*/
var permute = function (nums) {
let visited = new Array(nums.length).fill(false)
let reslut = []
let dfs = (nums, depth, len, path, visited) => {
if (depth == nums.length) {
reslut.push([...path])
}
for (let i = 0; i < len; i++) {
if (!visited[i]) {
path.push(nums[i])
visited[i] = true
dfs(nums, depth + 1, len, path, visited)
visited[i] = false
path.pop()
}
}
}
dfs(nums, 0, nums.length, [], visited)
return reslut
};
I struggled with two questions before:
1: When and how to switch from 1-2-3 to 1-3-2, especially the switch between 2 and 3 nodes. It can be seen from the above picture that it is the violent for loop
2: the order of backtracking: I will give an example in this question. When I
just finished 1-2-3 , the backtracking of the two visited is **[true,false,false] , At this time, the i of the second layer of for loop is 2**, which is followed by 3 in [1,2,3] , and then referring to visited
will select 2** in **[1,2,3].
Power button 17: The combination of letters of the phone number