Jan 12 - Summary Ranges;Array;String

Functions of StringBuilder:

代码：

public class Solution {
    public List<String> summaryRanges(int[] nums) {
        List<String> list = new ArrayList<>();
        if(nums.length == 0) return list;
        int head = 0;
        int k = -1;
        StringBuilder sb = new StringBuilder();
        for(int i = 0; i < nums.length; i++){
            if(i == 0){
                sb.append(nums[i]);
                if(i == nums.length-1){
                    list.add(sb.toString());
                    break;
                }
                sb.append(',');
                head = nums[i];
            }
            else if(nums[i] > head + 1){
                String[] tokens = sb.toString().split(",");
                if(tokens.length == 1) list.add(tokens[0]);
                if(tokens.length > 1){
                    String s = tokens[0]+"->"+tokens[tokens.length-1];
                    list.add(s);
                }
                sb = new StringBuilder();
                sb.append(nums[i]);
                if(i == nums.length-1){
                    list.add(sb.toString());
                    break;
                }
                sb.append(',');
                head = nums[i];
            }
            else{
                sb.append(nums[i]);
                if(i == nums.length-1){
                    String[] tokens = sb.toString().split(",");
                    String s = tokens[0]+"->"+tokens[tokens.length-1];
                    list.add(s);
                    break;
                }
                sb.append(',');
                head = nums[i];
            }
        }
        return list;
    }
}

　　网上的代码：

public class Solution {
    public List<String> summaryRanges(int[] nums) {
        List<String> list = new ArrayList<>();
        if(nums.length == 0) return list;
        int high = 0, low = 0;
        int length = nums.length;
        //int k = -1;
        while(high < length){
            if(high < length-1 && nums[high]+1 == nums[high+1]){
                high++;
            }
            else{
                if(low == high) list.add(String.valueOf(nums[high]));
                else list.add(nums[low]+"->"+nums[high]);
                high++;
                low = high;
            }
        }
        return list;
        
    }
}