주식가격

import java.util.*;

class Solution {
    public int[] solution(int[] prices) {
        int length = prices.length;
        int[] answer = new int[length];
        Queue<Integer> queue = new LinkedList<>();

        for (int i = 0; i < length; i++) {
            queue.add(prices[i]);
        }

        int red = 0;
        while (queue.size() > 0) {
            int price = queue.poll();
            for (int i = (length - queue.size()); i < length; i++) {
                if (price <= prices[i]) answer[red]++;
                else {
                    answer[red]++;
                    break;
                }
            }
            red++;
        }

        return answer;
    }
}

올바른 괄호

import java.util.*;

class Solution {
    boolean solution(String s) {
        Stack<Character> stack = new Stack<>();

        for (int i = 0; i < s.length(); i++) {
                if  (s.charAt(i) == '(') stack.push('(');
                else {
                    if(stack.isEmpty()) return false;
                    else stack.pop();
                }
        }
        
        return stack.isEmpty() ? true : false;
    }
}

프로세스

import java.util.*;

class Solution {
    public int solution(int[] priorities, int location) {
        int answer = 1;
        Queue<Integer> processes = new LinkedList<>();
        Queue<Integer> indexes = new LinkedList<>();
        
        for (int i = 0; i < priorities.length; i++) {
            processes.add(priorities[i]);
            indexes.add(i);
        }
        
        int max = Collections.max(processes);
        int process, index;
        
        while (!processes.isEmpty()) {
            process = processes.poll();
            index = indexes.poll();
            
            // if (process < max) {
            //     processes.add(process);
            //     indexes.add(index);
            // }
            // else {
            //     answer++;
            //     max = Collections.max(processes);
            //     if (index == location) return answer;
            // }
            // 순서를 바꾸면 타임아웃이 걸린다.
            
            if (process == max && index == location) {
                return answer;
            } 
            else if (process == max) {
                answer++;
                max = Collections.max(processes);
            }
            else {
                processes.add(process);
                indexes.add(index);
            }
        }
        
        return answer;
    }
}