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.
思路：
这道题的并不难，我们只需要判断nums[i]-1与nums[i-1]是否相等就可以知道他们是否再同一个区间，但是需要注意最后一个数的处理。
class Solution {
public:
vector<string> summaryRanges(vector<int>& nums) {
if(nums.size() == 0) return vector<string>();
int pre = 0;
vector<string> res;
for (int i = 1; i<int(nums.size()); i++) {
if (nums[i]-1 != nums[i - 1]) {
if (pre == i - 1) res.push_back(to_string(nums[pre]));
else res.push_back(to_string(nums[pre]) + "->" + to_string(nums[i-1]));
pre = i;
}
}
if(pre == nums.size()-1) res.push_back(to_string(nums.back()));
else res.push_back(to_string(nums[pre]) + "->" + to_string(nums.back()));
return res;
}
};