Java Code Style 记录

示例代码：

class Solution {
    /**
     * @param nums: A list of integers.
     * @return: A list of unique permutations.
     */
    public List<List<Integer>> permuteUnique(int[] nums) {
        // Write your code here
        ArrayList<List<Integer>> rst = new ArrayList<List<Integer>>();
        if (nums == null) {
            return rst;
        }
        if (nums.length == 0){
            rst.add(new ArrayList<Integer>());
            return rst;
        }
        Arrays.sort(nums);
        ArrayList<Integer> list = new ArrayList<Integer>();
        int[] visited = new int[nums.length];
        for (int i = 0; i < visited.length; i++) {
            visited[i] = 0;
        }
        helper(rst, list, visited, nums);
        return rst;
    }
    public void helper(ArrayList<List<Integer>> rst, List<Integer> list, int[] visited, int[] nums){
        if (list.size() == nums.length) {
            rst.add(new ArrayList<Integer>(list));
            return;
        }
        for (int i = 0; i < nums.length; i++) {
            if (visited[i] == 1 || (i != 0 && nums[i] == nums[i - 1] && visited[i - 1] == 0)){
                continue;
            }
            visited[i] = 1;
            list.add(nums[i]);
            helper(rst, list, visited, nums);
            list.remove(list.size() - 1);
            visited[i] = 0;
        }
    }
}

Code Style:

• for后有空格
• if后有空格
• 运算符前后有空格(+-*/,==,!=,)
• 逗号分号后有空格
• if for 的大括号不可省略(- -)

Bug Free:

• else/if后没有加括号导致只执行了第一条语句;
• for()里的参数没有先定义(有的时候需要在外面定义);

Google Java Style：https://my.oschina.net/candiesyangyang/blog/225058