leetcode/PermutationsII.java at master · gamblegear/leetcode

36 lines (31 loc) · 927 Bytes

public class Solution {

public ArrayList<ArrayList<Integer>> permuteUnique(int[] num) {

// Start typing your Java solution below

// DO NOT write main() function

ArrayList<Integer> cal = new ArrayList<Integer>();

ArrayList<ArrayList<Integer>> re = new ArrayList<ArrayList<Integer>>();

Arrays.sort(num);

int len = num.length;

int[] used = new int[len];

getpermute(num, used, len, cal, re);

return re;

}

public void getpermute(int[] num, int[] used, int len, ArrayList<Integer> cal, ArrayList<ArrayList<Integer>> re){

if(cal.size() == len){

ArrayList<Integer> temp = new ArrayList<Integer>(cal);

re.add(temp);

return;

}

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

if(used[i] == 0){

cal.add(num[i]);

used[i]=1;

getpermute(num,used,len,cal,re);

used[i]=0;

cal.remove(cal.size()-1);

while(i<len-1 && num[i]==num[i+1])

i++;

}

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