LeetCode 163. Missing Ranges

Two pointers.

#include <vector>#include <string>#include <iostream>using namespace std;/*  Given a sorted integer array where the range of element are [lower, upper] inclusive,  return its missing ranges.  For example, given [0, 1, 3, 50, 75], lower = 0 and upper = 99.  return ["2", "4->49", "51->74", "76->99"];*/vector<string> missingRanges(vector<int>& nums, int low, int high) {  if(nums.size() == 0) return {to_string(low) + "->" + to_string(high)};  vector<string> res;  int start = low;  int end = nums[0];  for(int i = 0; i < nums.size(); ++i) {    if(end - start >= 2) {      string tmp = to_string(start) + "->" + to_string(end - 1);      res.push_back(tmp);    }    start = end + 1;    end = nums[i];  }  if(end - start >= 2) {    string tmp = to_string(start) + "->" + to_string(end - 1);    res.push_back(tmp);  }  if(high - end >= 2) {    string tmp = to_string(end + 1) + "->" + to_string(high);    res.push_back(tmp);  } else if(high - end >= 1) res.push_back(to_string(high));  return res;}int main(void) {  vector<int> nums {0, 1, 2, 5, 99};  vector<string> res = missingRanges(nums, 0, 100);  for(string s : res) cout << s << endl;}