Classes and Objects in C++ HackerRank Solution
A class defines a blueprint for an object. We use the same syntax to declare objects of a class as we use to declare variables of other basic types. For example:
Box box1; // Declares variable box1 of type Box
Box box2; // Declare variable box2 of type Box
Kristen is a contender for valedictorian of her high school. She wants to know how many students (if any) have scored higher than her in the 5 exams given during this semester.
Create a class named students with the following specifications:
-
An instance variable named scores to hold a student's 5 exam scores.
-
A void input() function that reads 5 integers and saves them to scores.
-
An int calculateTotalScore() function that returns the sum of the student's scores.
Input Format
Most of the input is handled for you by the locked code in the editor.
In the void Student::input() function, you must read 5 scores from stdin and save them to your scores instance variable.
Constraints
1 <= n <= 100
0 <= examscore <= 50
Output Format
In the int Student::calculateTotalScore() function, you must return the student's total grade (the sum of the values in scores).
The locked code in the editor will determine how many scores are larger than Kristen's and print that number to the console.
Sample Input
The first line contains n, the number of students in Kristen's class. The n subsequent lines contain each student's 5 exam grades for this semester.
3
30 40 45 10 10
40 40 40 10 10
50 20 30 10 10
Sample Output
1
Explaination
Kristen's grades are on the first line of grades. Only 1 student scored higher than her.
Solution
#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <cassert>
using namespace std;
// Write your Student class here
class Student {
private:
vector<int> scores;
public:
void input() {
for (int i = 0; i < 5; i++) {
int score;
cin >> score;
scores.push_back(score);
}
}
int calculateTotalScore() {
int total = 0;
for (int i = 0; i < 5; i++) {
total += scores[i];
}
return total;
}
};
int main() {
int n; // number of students
cin >> n;
Student *s = new Student[n]; // an array of n students
for(int i = 0; i < n; i++){
s[i].input();
}
// calculate kristen's score
int kristen_score = s[0].calculateTotalScore();
// determine how many students scored higher than kristen
int count = 0;
for(int i = 1; i < n; i++){
int total = s[i].calculateTotalScore();
if(total > kristen_score){
count++;
}
}
// print result
cout << count;
return 0;
}
