[C++][Implementation] Grading Students

https://www.hackerrank.com/challenges/grading/problem

 

#include <bits/stdc++.h>
 
using namespace std;
 
string ltrim(const string &);
string rtrim(const string &);
 
/*
 * Complete the 'gradingStudents' function below.
 *
 * The function is expected to return an INTEGER_ARRAY.
 * The function accepts INTEGER_ARRAY grades as parameter.
 */
 
vector<int> gradingStudents(vector<int> grades) {
 
  int sNum = grades.size();
  vector<int> roundedGrade(sNum);
 
  for (int i = 0; i < sNum; i++) {
    if (grades[i] < 38) {
      roundedGrade[i] = grades[i];
    }
    else {
        int re = grades[i] % 5;
        if (re > 2) {
            // when re == 4 or re == 3
            roundedGrade[i] = grades[i] + (5 - re);
        }
        else {
            roundedGrade[i] = grades[i];
        }
    }
  }
  
  return roundedGrade;
}
 
int main()
{
    ofstream fout(getenv("OUTPUT_PATH"));
 
    string grades_count_temp;
    getline(cin, grades_count_temp);
 
    int grades_count = stoi(ltrim(rtrim(grades_count_temp)));
 
    vector<int> grades(grades_count);
 
    for (int i = 0; i < grades_count; i++) {
        string grades_item_temp;
        getline(cin, grades_item_temp);
 
        int grades_item = stoi(ltrim(rtrim(grades_item_temp)));
 
        grades[i] = grades_item;
    }
 
    vector<int> result = gradingStudents(grades);
 
    for (size_t i = 0; i < result.size(); i++) {
        fout << result[i];
 
        if (i != result.size() - 1) {
            fout << "\n";
        }
    }
 
    fout << "\n";
 
    fout.close();
 
    return 0;
}
 
string ltrim(const string &str) {
    string s(str);
 
    s.erase(
        s.begin(),
        find_if(s.begin(), s.end(), not1(ptr_fun<int, int>(isspace)))
    );
 
    return s;
}
 
string rtrim(const string &str) {
    string s(str);
 
    s.erase(
        find_if(s.rbegin(), s.rend(), not1(ptr_fun<int, int>(isspace))).base(),
        s.end()
    );
 
    return s;
}