Lecture Note solution

lectureNote.cpp

// https://algospot.com/judge/problem/read/LECTURE
// Time Complexity : O(nlogn)
// Space Complexity : O(n)

#include <string>
#include <vector>
#include <iostream>
#include <algorithm>

using namespace std;

struct Comp {
  bool operator () (string i, string j) { return (i < j); }
} comp;

string sortedString(const string &str) {
  int length = str.length();
  string sortedStr;
  if (length > 1000 || length%2 != 0) return sortedStr;

  vector<string> v;
  for (int i = 0; i < length; i += 2) {
    v.push_back(str.substr(i, 2));
  }

  sort(v.begin(), v.end(), comp);

  for (vector<string>::iterator it = v.begin(); it != v.end(); it++) {
    sortedStr += *it;
  }
  
  return sortedStr;
}

int main(void) {
  int testCount, i;
  string str;
  vector<string> v;
  cin >> testCount;
  for (i = 0; i < testCount; i++) {
    cin >> str;
    v.push_back(sortedString(str)); 
  }

  for (vector<string>::iterator it = v.begin(); it != v.end(); it++) {
    cout << *it << endl;
  }
  return 0;
}