[백준][Java] 15904번 UCPC는 무엇의 약자일까? (문자열)

시간 단축

 

Stack으로 push할 필요 없이(넣는 동작으로 시간 늘어남)

count로 처리함

 

i번째에 넣을 수 있는 알파벳은

조건문으로 인해 반드시 정해져 있기 때문에 

count로 ++만 해줘서 몇번째 알파벳인지만 체크 

 

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
 
 
public class Main {
    
    private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    private static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
 
    
 
    public static void main(String[] args) throws IOException{
        char[] arr = br.readLine().toCharArray();
        int count = 0;
        
        for (char c : arr) {
            if(c=='U' && count==0)
                count++;
            else if(c=='C') {
                if(count==1)
                    count++;
                else if(count==3){
                    System.out.println("I love UCPC");
                    return ;
                }
            }
            else if(c=='P' && count==2 )
                count++;
        }
        
        System.out.println("I hate UCPC");
        
        
//        bw.write("");
//        bw.flush();
//        bw.close();
    }
    
 
//    private static int stoi(String input) {
//        return Integer.parseInt(input);
//    }
}

 

↑ 수정

 

 

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Stack;
 
 
public class Main {
    
    private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    private static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
 
    
 
    public static void main(String[] args) throws IOException{
        char[] arr = br.readLine().toCharArray();
        Stack<Character> st = new Stack<>();
        
        for (char c : arr) {
            if(c=='U' && st.size()==0)
                st.push('U');
            else if(c=='C') {
                if(st.size()==1 && st.peek()=='U')
                    st.push('C');
                else if(st.size()==3 && st.peek()=='P'){
                    System.out.println("I love UCPC");
                    return ;
                }
            }
            else if(c=='P' && st.size()==2 && st.peek()=='C')
                st.push('P');
        }
        
        System.out.println("I hate UCPC");
        
        
//        bw.write("");
//        bw.flush();
//        bw.close();
    }
    
 
//    private static int stoi(String input) {
//        return Integer.parseInt(input);
//    }
}