프로그래머스 java - 다항식 더하기

체감 Level : ★ ★ ☆ Review: 조건이 정말 정말 까다롭다. 문자랑 숫자랑 섞여있어서 변환할때 오류나고 장난아니었다. 반례 위주로 찾아보면서 여러차례 수정하니까 결국 성공 !! ㅜㅜ

 

💡 다항식이 주어질때 동류항끼리 계산해서 출력하는 코드를 짜시오.

 

 

[성공]

class Solution {
    public String solution(String polynomial) {
        String answer = "";

        String[] str = polynomial.split("\\+");
        String s1 = "";
        
        for (String s : str){
            s1 += s;
        }
        
        int x = 0, xsum = 0, n = 0, nsum = 0;
        int xflag =0, nflag = 0;
        int cnt = 0;
    
        String[] str2 = s1.split(" ");
        
        for (String s : str2){
            if (s.contains("x")){
                xflag = 1;
                String tmp = "";
            
               // x 자릿수 확인
                for (int i =0 ; i<s.length(); i++){
                    if(s.charAt(i) != 'x'){
                        cnt++;
                    }
                }

                // x 랑 같다면
                if (s.equals("x")){
                    //answer += s;
                    xsum += 1;
                }else { // x 랑 같지 않다면.. (자리수)
                    if (cnt == 1){
                        xsum += (int)s.charAt(0)-48;
                        cnt = 0;
                    }else if (cnt == 2){
                        xsum += Integer.valueOf(s.substring(0,2));
                        cnt = 0;
                    }
                    
                     
                    //answer += s;
                }
            }else{
                
              if (!s.isEmpty()){
                    nsum += Integer.valueOf(s);
                    nflag=1;
              }
            }
        }
        
        if ( nflag == 1  && xflag == 1){
            if (xsum == 1){
                answer += "x + " + nsum; 
            }else{
                answer += String.valueOf(xsum) + "x";
                answer += " + " + nsum;     
            }
            
        }else if ( nflag == 1){
            answer += nsum; 
        }else if ( xflag == 1){
            if (xsum == 1){
                answer += "x";
            }else{
                answer += String.valueOf(xsum) + "x";    
            }
            
        }
        
        return answer;
    }
}

 

 

 

[실패]  1x ->  x 가 나와야한다.

class Solution {
    public String solution(String polynomial) {
        String answer = "";
        
        String[] str = polynomial.split("\\+");
        String s1 = "";
        for (String s : str){
            s1 += s;
        }
        
        int x = 0;
        int xsum = 0;
        int n = 0;
        int nsum = 0;
        int xflag =0, nflag = 0;
        int cnt = 0;
        
        
        String[] str2 = s1.split(" ");
        for (String s : str2){
            if (s.contains("x")){
                xflag = 1;
                String tmp = "";
            
               // x 자릿수 확인
                for (int i =0 ; i<s.length(); i++){
                    if(s.charAt(i) != 'x'){
                        cnt++;
                    }
                }

               
                // x 랑 같다면
                if (s.equals("x")){
                    //answer += s;
                    xsum += 1;
                }else { // x 랑 같지 않다면.. (자리수)
                    if (cnt == 1){
                        xsum += (int)s.charAt(0)-48;
                        cnt = 0;
                    }else if (cnt == 2){
                        xsum += Integer.valueOf(s.substring(0,2));
                        cnt = 0;
                    }
                     
                    //answer += s;
                }
            }else{
                
              if (!s.isEmpty()){
                    nsum += Integer.valueOf(s);
                    nflag=1;
              }
            }
        }
        
        if ( nflag == 1  && xflag == 1){
            if (xsum == 1){
                answer += "x + " + nsum; 
            }else{
                answer += String.valueOf(xsum) + "x";
                answer += " + " + nsum;     
            }
            
        }else if ( nflag == 1){
            answer += nsum; 
        }else if ( xflag == 1){
            answer += String.valueOf(xsum) + "x";
        }
      
        return answer;
    }
}

 

[실패]

class Solution {
    public String solution(String polynomial) {
        String answer = "";
        
        String[] str = polynomial.split("\\+");
        String s1 = "";
        for (String s : str){
            s1 += s;
        }
        
        int x = 0;
        int xsum = 0;
        int n = 0;
        int nsum = 0;
        int xflag =0, nflag = 0;
        
        String[] str2 = s1.split(" ");
        for (String s : str2){
            if (s.contains("x")){
                xflag = 1;
                if (s.equals("x")){
                    //answer += s;
                    xsum += 1;
                }else {
                    xsum += (int)s.charAt(0)-48;
                    //answer += s;
                }
            }else{
                
              if (!s.isEmpty()){
                    nsum += Integer.valueOf(s);
                    nflag=1;
              }
            }
        }
        if ( nflag == 1  && xflag == 1){
            if (xsum == 1){
                answer += "x + " + nsum; 
            }else{
                answer += String.valueOf(xsum) + "x";
                answer += " + " + nsum;     
            }
            
        }else if ( nflag == 1){
            answer += nsum; 
        }else if ( xflag == 1){
            answer += String.valueOf(xsum) + "x";
        }
      
        return answer;
    }
}

 

 

 

 

[실패]

class Solution {
    public String solution(String polynomial) {
        String answer = "";
        
        String[] str = polynomial.split("\\+");
        String s1 = "";
        for (String s : str){
            s1 += s;
        }
        
        int x = 0;
        int xsum = 0;
        int n = 0;
        int nsum = 0;
        int xflag =0, nflag = 0;
        
        String[] str2 = s1.split(" ");
        for (String s : str2){
            if (s.contains("x")){
                xflag = 1;
                if (s.equals("x")){
                    //answer += s;
                    xsum += 1;
                }else {
                    xsum += (int)s.charAt(0)-48;
                    //answer += s;
                }
            }else{
                
              if (!s.isEmpty()){
                    nsum += Integer.valueOf(s);
                    nflag=1;
              }
            }
        }
        if ( nflag == 1  && xflag == 1){
            answer += String.valueOf(xsum) + "x";
            answer += " + " + nsum; 
        }else if ( nflag == 1){
            answer += nsum; 
        }else if ( xflag == 1){
            answer += String.valueOf(xsum) + "x";
        }
      
        return answer;
    }
}