int cmp (const void * a, const void * b){return ( *(int*)a - *(int*)b );}
int** permuteUnique(int* nums, int numsSize, int* returnSize) {
    int size=1,i=0,count=1,d=1;
    qsort(nums,numsSize,sizeof(int),cmp);
    for(;i<numsSize-1;i++){
        if(nums[i]!=nums[i+1])d++;
    }
    for(i=numsSize;i>1;i--)size*=i;
    size=size/((numsSize>d&&d!=1)?pow(2,numsSize-d):1);
    int **a=(int **)malloc(size*sizeof(int *));
    int **b=(int **)malloc(size*sizeof(int *));
    int **c=NULL;
    for(i=0;i<size;i++)
	{
        a[i]=(int *)malloc((numsSize)*sizeof(int));
        b[i]=(int *)malloc((numsSize)*sizeof(int));
	}
    for(i=0;i<numsSize;i++){//s樹的層數 i
        int cc=0;
        for (int k=0;k<count;k++)//當前的答案數 k
        {
			int jishu=0;
			for (int l=0;l<numsSize;l++)//nums陣列中元素個數 l
			{
				if(jishu>0&&nums[b[cc-1][i]]==nums[l])continue;
				int j=0;
                for (;j<i;j++)//當前答案的節點數j
				{
					if (a[k][j]==l)break;
				} 
                if (j>=i)
				{
					memcpy(b[cc],a[k],sizeof(int)*i);
					b[cc++][i]=l;
					jishu++;
				}
			}
        }
		count=cc;c=a;a=b;b=c;
    }
	*returnSize=count;
	for(i=0;i<count;i++){
		for (int j=0;j<numsSize;j++)
		{
			a[i][j]=nums[a[i][j]];
		}
	}
    return a;
}