228. Summary Ranges
摘要：
Given a sorted integer array without duplicates, return the summary of its ranges.
Example 1:
Input:[0,1,2,4,5,7]
Output: ["0->...
Given a sorted integer array without duplicates, return the summary of its ranges.
Example 1:
Input:[0,1,2,4,5,7] Output: ["0->2","4->5","7"] Explanation: 0,1,2 form a continuous range; 4,5 form a continuous range.
Example 2:
Input:[0,2,3,4,6,8,9] Output: ["0","2->4","6","8->9"] Explanation: 2,3,4 form a continuous range; 8,9 form a continuous range.
難度：medium
題目：給定排序且無重複元素的整數陣列，返回其連續元素的範圍。
思路：用以變數記錄連續元素的開始。
Runtime: 5 ms, faster than 7.57% of Java online submissions for Summary Ranges.
Memory Usage: 37.5 MB, less than 5.02% of Java online submissions for Summary Ranges.
class Solution {
public List<String> summaryRanges(int[] nums) {
List<String> result = new ArrayList<>();
if (null == nums || nums.length < 1) {
return result;
}
for (int i = 1, start = 0; i <= nums.length; i++) {
if (i == nums.length || nums[i] - nums[i - 1] != 1) {
result.add((i - 1 == start) ? String.format("%s", nums[start])
: String.format("%s->%s", nums[start], nums[i - 1]));
start = i;
}
}
return result;
}
}