public List<String> summaryRanges(int[] nums) {
		List<String> rtList = new ArrayList<String>();
		String range = "";
		int range_1 = 0;
		for (int i = 0; i < nums.length; i++) {
			if (nums.length == 1) {
				range_1 = nums[i];
				range = range_1 + "";
				rtList.add(range);
				break;
			}
			
			if (i == 0) {
				range_1 = nums[i];
			} else if (nums[i] - nums[i - 1] != 1) {
				if (range_1 != nums[i-1]) {
					range = range_1 + "->" + nums[i-1];
				} else {
					range = range_1 + "";
				}
				rtList.add(range);
				range_1 = nums[i];
				if(i == nums.length - 1){
					range = range_1 + "";
					rtList.add(range);
				}
			} else if (nums[i] - nums[i-1] == 1 && i == nums.length - 1) {
				range = range_1 + "->" + nums[i];
				rtList.add(range);
			} 
		}
		return rtList;
	}