The school cafeteria offers circular and square sandwiches at lunch break, referred to by numbers 0 and 1 respectively. All students stand in a queue. Each student either prefers square or circular sandwiches. The number of sandwiches in the cafeteria is equal to the number of students. You are given two integer arrays students and sandwiches where sandwiches[i] is the type of the i​​​​​​th sandwich in the stack (i = 0 is the top of the stack) and students[j] is the preference of the j​​​​​​th student in the initial queue (j = 0 is the front of the queue). Part 1: Modify the code given and make it more efficient. You can try to implement your own stack or your own Queue. Or you can use the sandwiches array as a stack without making a separate Stack class. Same with the students array.  Part 2: After modifying the code, explain how it works, and why it is more efficient than the solution that you started with. (Or, if it turns out that the change you made is not more efficient, try to explain why that might be).

Database System Concepts
7th Edition
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Chapter1: Introduction
Section: Chapter Questions
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The school cafeteria offers circular and square sandwiches at lunch break, referred to by numbers 0 and 1 respectively. All students stand in a queue. Each student either prefers square or circular sandwiches. The number of sandwiches in the cafeteria is equal to the number of students. You are given two integer arrays students and sandwiches where sandwiches[i] is the type of the i​​​​​​th sandwich in the stack (i = 0 is the top of the stack) and students[j] is the preference of the j​​​​​​th student in the initial queue (j = 0 is the front of the queue).

  • Part 1: Modify the code given and make it more efficient. You can try to implement your own stack or your own Queue. Or you can use the sandwiches array as a stack without making a separate Stack class. Same with the students array. 
  • Part 2: After modifying the code, explain how it works, and why it is more efficient than the solution that you started with. (Or, if it turns out that the change you made is not more efficient, try to explain why that might be).
class Solution {
public int countStudents (int[] students, int[] sandwiches) {
Stack<Integer> sammies = new Stack<Integer>();
for(int i = sandwiches.length - 1; i >= 0; i--) {
sammies.push(sandwiches [i]);
}
}
}
Queue<Integer> hungryStudents = new Linked List<Integer>();
for(int j = 0; j < students.length; j++) {
hungryStudents.add(students [j]);
}
boolean isHope = true;
while (!sammies.isEmpty() && isHope) {
int numHungryStudents = hungryStudents.size();
for (int s = 0; s < numHungryStudents; s++) {
int student = hungryStudents.remove();
if(student == sammies.peek()) {
sammies.pop();
}
else {
}
}
return
hungryStudents.add(student);
}
if (numHungryStudents
isHope = false;
==
hungryStudents.size();
hungryStudents.size())
Transcribed Image Text:class Solution { public int countStudents (int[] students, int[] sandwiches) { Stack<Integer> sammies = new Stack<Integer>(); for(int i = sandwiches.length - 1; i >= 0; i--) { sammies.push(sandwiches [i]); } } } Queue<Integer> hungryStudents = new Linked List<Integer>(); for(int j = 0; j < students.length; j++) { hungryStudents.add(students [j]); } boolean isHope = true; while (!sammies.isEmpty() && isHope) { int numHungryStudents = hungryStudents.size(); for (int s = 0; s < numHungryStudents; s++) { int student = hungryStudents.remove(); if(student == sammies.peek()) { sammies.pop(); } else { } } return hungryStudents.add(student); } if (numHungryStudents isHope = false; == hungryStudents.size(); hungryStudents.size())
Example 1:
Input: students = [1,1,0,0], sandwiches = [0,1,0,1]
Output: 0
Explanation:
Front student leaves the top sandwich and returns to the end of the line
making students = [1,0,0,1].
- Front student leaves the top sandwich and returns to the end of the line
making students = [0,0,1,1].
- Front student takes the top sandwich and leaves the line making students =
[0,1,1] and sandwiches = [1,0,1].
Front student leaves the top sandwich and returns to the end of the line
making students = [1,1,0].
- Front student takes the top sandwich and leaves the line making students =
[1,0] and sandwiches = [0,1].
- Front student leaves the top sandwich and returns to the end of the line
making students = [0,1].
Front student takes the top sandwich and leaves the line making students =
[1] and sandwiches = [1].
Front student takes the top sandwich and leaves the line making students =
[] and sandwiches = [].
Hence all students are able to eat.
Example 2:
Input: students = [1,1,1,0,0,1], sandwiches = [1,0,0,0,1,1]
Output: 3
Transcribed Image Text:Example 1: Input: students = [1,1,0,0], sandwiches = [0,1,0,1] Output: 0 Explanation: Front student leaves the top sandwich and returns to the end of the line making students = [1,0,0,1]. - Front student leaves the top sandwich and returns to the end of the line making students = [0,0,1,1]. - Front student takes the top sandwich and leaves the line making students = [0,1,1] and sandwiches = [1,0,1]. Front student leaves the top sandwich and returns to the end of the line making students = [1,1,0]. - Front student takes the top sandwich and leaves the line making students = [1,0] and sandwiches = [0,1]. - Front student leaves the top sandwich and returns to the end of the line making students = [0,1]. Front student takes the top sandwich and leaves the line making students = [1] and sandwiches = [1]. Front student takes the top sandwich and leaves the line making students = [] and sandwiches = []. Hence all students are able to eat. Example 2: Input: students = [1,1,1,0,0,1], sandwiches = [1,0,0,0,1,1] Output: 3
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