[백준] 17144 - 미세먼지 안녕!

17144번: 미세먼지 안녕!

• 코드

  package review;
  
  import java.io.BufferedReader;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.StringTokenizer;
  
  public class ex_17144 {
      static int R,C,T,answer;
      static int[][]room;
      static int[]clean;
      static int[]dx={1,-1,0,0};
      static int[]dy={0,0,1,-1};
      public static void main(String[] args) throws IOException {
          System.setIn(new FileInputStream("input/17144.txt"));
          BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
          StringTokenizer st = new StringTokenizer(br.readLine());
          R = Integer.parseInt(st.nextToken());
          C = Integer.parseInt(st.nextToken());
          T = Integer.parseInt(st.nextToken());
          answer=0;
          clean=new int[2];
          room=new int[R][C];
          int index=0;
  
          for(int i=0;i<R;i++){
              st = new StringTokenizer(br.readLine());
              for(int j=0;j<C;j++){
                  room[i][j]=Integer.parseInt(st.nextToken());
                  if(room[i][j]==-1) clean[index++]=i;
              }
          }
          for(int i=0;i<T;i++){
              spread();
              turn();
          }
          count();
          System.out.println(answer+2);
      }static void spread(){
          int[][]temp=new int[R][C];
          for(int i=0;i<R;i++){
              for(int j=0;j<C;j++){
                  if(room[i][j]>0){
                      int add=room[i][j]/5;
                      int c=0;
                      for(int k=0;k<4;k++){
                          int cx=dx[k]+i;
                          int cy=dy[k]+j;
                          if(check(cx,cy)){
                              if(cx==clean[0] && cy==0) continue;
                              if(cx==clean[1] && cy==0) continue;
                              temp[cx][cy]+=add;
                              c++;
                          }
                      }
                      temp[i][j]+=room[i][j]-add*c;
                  }
              }
          }
          copy(temp);
      }static void turn(){
          int[][]temp=new int[R][C];
          temp[0][C-1]=room[1][C-1];
          temp[R-1][C-1]=room[R-2][C-1];
          temp[1][0]=room[0][0];
          temp[R-2][0]=room[R-1][0];
  
          for(int j=1;j<C-1;j++){ //우
              temp[clean[0]][j+1]=room[clean[0]][j];
              temp[clean[1]][j+1]=room[clean[1]][j];
          }
          for(int i=0;i<clean[0];i++){ //상
              temp[i][C-1]=room[i+1][C-1];
          }
          for(int i=clean[1]+1;i<R;i++){
              temp[i][C-1]=room[i-1][C-1];
          }
          for(int j=0;j<C-1;j++){ //좌
              temp[0][j]=room[0][j+1];
              temp[R-1][j]=room[R-1][j+1];
          }
          for(int i=1;i<clean[0];i++){ //하
              temp[i][0]=room[i-1][0];
          }
          for(int i=clean[1]+1;i<R-1;i++) {
              temp[i][0] = room[i + 1][0];
          }
          copy2(temp);
      }static void count(){
          for(int i=0;i<R;i++){
              for(int j=0;j<C;j++) {
                  answer+=room[i][j];
              }
          }
      }static boolean check(int x, int y){
          if(x<0 || y<0 || x>=R || y>=C) return false;
          return true;
      }static void copy(int [][]temp){
          for(int i=0;i<R;i++){
              for(int j=0;j<C;j++){
                  room[i][j]=temp[i][j];
              }
          }
          room[clean[0]][0]=-1;
          room[clean[1]][0]=-1;
      }static void copy2(int [][]temp){
          for(int i=0;i<R;i++){
              if(i==0 || i==clean[0] ||i==clean[1] || i==R-1) {
                  for(int j=0;j<C;j++){
                      room[i][j]=temp[i][j];
                  }
              }else{
                  room[i][0]=temp[i][0];
                  room[i][C-1]=temp[i][C-1];
              }
          }
          room[clean[0]][0]=-1;
          room[clean[1]][0]=-1;
      }
  }

• 아이디어
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