用Permutations的思路就能解决,代码不用改。
代码:
public void permute_array(int[] nums, int len){
if(flag) return;
List<Integer> list = new ArrayList<>();
for(int i = 0; i < nums.length; i++) list.add(nums[i]);
resultList.add(list);
int maxIndex = len - 1, minIndex = len -1;
int max = nums[maxIndex];
int min = nums[minIndex];
for(int i = len-1; i>=0; i--){
if(nums[i] < min){
nums[minIndex] = nums[i];
nums[i] = min;
permute_array(nums, len);
}
if(nums[i] < max){
int j = maxIndex;
while(j >= 1 && nums[i] < nums[j-1]) j--;
int temp = nums[i];
nums[i] = nums[j];
nums[j] = temp;
permute_array(nums, len);
}
else{
if(i == 0) flag = true;;
max = nums[i];
for(int j = i;j < len-1; j++) nums[j] = nums[j+1];
nums[len-1] = max;
minIndex = i;
maxIndex = len-1;
}
}
}