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Student-Course Pairs
const studentCoursePairs1 = [
["58", "Linear Algebra"],
["94", "Art History"],
["94", "Operating Systems"],
["17", "Software Design"],
["58", "Mechanics"],
["58", "Economics"],
["17", "Linear Algebra"],
["17", "Political Science"],
["94", "Economics"],
["25", "Economics"],
["58", "Software Design"]
];
const studentCoursePairs2 = [
["42", "Software Design"],
["0", "Advanced Mechanics"],
["9", "Art History"],
];
function findPairs(studentCoursePairs) {
const result = new Map(); // {[student id pair], [courses]}
let studentIds = new Set();
function findSharedCourses(studentPair, studentCoursePairs) {
const counts = {};
const sharedCourses = [];
// Updates course counts for the given student pair
for (const [studentId, course] of studentCoursePairs) {
if (studentId === studentPair[0] || studentId === studentPair[1]) {
counts[course] = counts[course] ? counts[course] + 1 : 1;
}
}
// Add courses that both students have
for (const course in counts) {
if (counts[course] === 2) {
sharedCourses.push(course);
}
}
return sharedCourses;
}
// 1. Get unique student ids
for (const pair of studentCoursePairs) {
studentIds.add(pair[0]);
}
studentIds = [...studentIds];
// 2. For each student pair find shared courses and add to the result
while (studentIds.length) {
for (let j = 1; j < studentIds.length; j++) {
const studentPair = [studentIds[0], studentIds[j]];
const sharedCourses = findSharedCourses(studentPair, studentCoursePairs);
result.set(studentPair, sharedCourses);
}
// All pairs have been created for the current student, remove them
studentIds.splice(0, 1);
}
return result;
}
console.log(findPairs(studentCoursePairs1));
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