A PHP Error was encountered

Severity: Warning

Message: mkdir(): Permission denied

Filename: libraries/Common.php

Line Number: 202

Backtrace:

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 202
Function: mkdir

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 236
Function: getLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 585
Function: parseLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 425
Function: initBoardView

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: file_put_contents(/DATA/upload/polymath/latex/4ec8f006c2cb936048c45fb2e29ca197.gif): failed to open stream: No such file or directory

Filename: libraries/Common.php

Line Number: 213

Backtrace:

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 213
Function: file_put_contents

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 236
Function: getLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 585
Function: parseLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 425
Function: initBoardView

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: mkdir(): Permission denied

Filename: libraries/Common.php

Line Number: 202

Backtrace:

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 202
Function: mkdir

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 236
Function: getLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 585
Function: parseLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 425
Function: initBoardView

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: file_put_contents(/DATA/upload/polymath/latex/ea02f5f09fa635e33c4857ec99404ad9.gif): failed to open stream: No such file or directory

Filename: libraries/Common.php

Line Number: 213

Backtrace:

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 213
Function: file_put_contents

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 236
Function: getLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 585
Function: parseLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 425
Function: initBoardView

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: mkdir(): Permission denied

Filename: libraries/Common.php

Line Number: 202

Backtrace:

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 202
Function: mkdir

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 236
Function: getLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 585
Function: parseLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 425
Function: initBoardView

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: file_put_contents(/DATA/upload/polymath/latex/e844b5729612882c413603ed07594bfe.gif): failed to open stream: No such file or directory

Filename: libraries/Common.php

Line Number: 213

Backtrace:

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 213
Function: file_put_contents

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 236
Function: getLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 585
Function: parseLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 425
Function: initBoardView

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: mkdir(): Permission denied

Filename: libraries/Common.php

Line Number: 202

Backtrace:

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 202
Function: mkdir

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 236
Function: getLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 585
Function: parseLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 425
Function: initBoardView

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
Line: 315
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: file_put_contents(/DATA/upload/polymath/latex/8792fb1688710449c3a31f5a98c2423b.gif): failed to open stream: No such file or directory

Filename: libraries/Common.php

Line Number: 213

Backtrace:

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 213
Function: file_put_contents

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
Line: 236
Function: getLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 585
Function: parseLatexImg

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
Line: 425
Function: initBoardView

File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
Line: 315
Function: require_once

함께 풀고 싶은 문제
깊이 고민해볼 수 있는 수학 문제를 내는 곳입니다
[세상을 바꿀 문제] 전등 켜기
김미래_기자 2021.07.13 03:05 조회 1059

전등이 n   imes n 형태로 배치되어 있습니다. 하나의 전등을 선택하면 그 전등을 포함한 가로줄과 세로줄의 전등 2n-1개의 상태가 바뀝니다.(즉, 켜져있던 전등은 꺼지고 꺼져있던 전등은 켜집니다). 초기에 모든 전등이 꺼져있습니다.

 

1) n=7일 때 모든 전등을 켜기 위해서 최소한 몇 번의 시행을 해야할까요?

2) n=8일 때 모든 전등을 켜기 위해서 최소한 몇 번의 시행을 해야할까요?

 

 

출제자 : 김다인 멘토

이 문제 어떠셨나요?

글쎄요

0

어려워요

0

  •  
    부분해결
    JM Lv.6 2021.07.13 03:51 비밀댓글
    비밀 댓글이 등록 되었습니다.
    댓글 작성하기 댓글수2
  •  
    다시 도전
    17수락 Lv.9 2021.07.13 18:27 비밀댓글
    비밀 댓글이 등록 되었습니다.
    댓글 작성하기 댓글수1
    •  
      김다인(멘토) Lv.15 2021.07.13 19:11 비밀댓글
      비밀 댓글이 등록 되었습니다!
  •  
    부분해결
    JM Lv.6 2021.07.15 00:31 비밀댓글
    비밀 댓글이 등록 되었습니다.
    댓글 작성하기 댓글수1
    •  
      김다인(멘토) Lv.15 2021.07.15 03:02 비밀댓글
      비밀 댓글이 등록 되었습니다!
  •  
    부분해결
    쓰다만연습장 Lv.5 2021.07.18 10:24 비밀댓글
    비밀 댓글이 등록 되었습니다.
    댓글 작성하기 댓글수1
    •  
      김다인(멘토) Lv.15 2021.07.19 19:35 비밀댓글
      비밀 댓글이 등록 되었습니다!
  •  
    해결
    hehehe Lv.5 2021.09.18 08:01 비밀댓글

    A PHP Error was encountered

    Severity: Warning

    Message: mkdir(): Permission denied

    Filename: libraries/Common.php

    Line Number: 202

    Backtrace:

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
    Line: 202
    Function: mkdir

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
    Line: 236
    Function: getLatexImg

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/views/ver3/inc/view_comment_list.php
    Line: 90
    Function: parseLatexImg

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/views/ver3/inc/view.php
    Line: 343
    Function: view

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
    Line: 558
    Function: view

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
    Line: 315
    Function: require_once

    A PHP Error was encountered

    Severity: Warning

    Message: file_put_contents(/DATA/upload/polymath/latex/e1cb3cb5bd6b11b6120204e1ef7e8488.gif): failed to open stream: No such file or directory

    Filename: libraries/Common.php

    Line Number: 213

    Backtrace:

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
    Line: 213
    Function: file_put_contents

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
    Line: 236
    Function: getLatexImg

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/views/ver3/inc/view_comment_list.php
    Line: 90
    Function: parseLatexImg

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/views/ver3/inc/view.php
    Line: 343
    Function: view

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
    Line: 558
    Function: view

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
    Line: 315
    Function: require_once

    A PHP Error was encountered

    Severity: Warning

    Message: mkdir(): Permission denied

    Filename: libraries/Common.php

    Line Number: 202

    Backtrace:

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
    Line: 202
    Function: mkdir

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
    Line: 236
    Function: getLatexImg

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/views/ver3/inc/view_comment_list.php
    Line: 90
    Function: parseLatexImg

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/views/ver3/inc/view.php
    Line: 343
    Function: view

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
    Line: 558
    Function: view

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
    Line: 315
    Function: require_once

    A PHP Error was encountered

    Severity: Warning

    Message: file_put_contents(/DATA/upload/polymath/latex/2ce0818baae7d665eacb70dfff34e3ea.gif): failed to open stream: No such file or directory

    Filename: libraries/Common.php

    Line Number: 213

    Backtrace:

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
    Line: 213
    Function: file_put_contents

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
    Line: 236
    Function: getLatexImg

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/views/ver3/inc/view_comment_list.php
    Line: 90
    Function: parseLatexImg

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/views/ver3/inc/view.php
    Line: 343
    Function: view

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
    Line: 558
    Function: view

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
    Line: 315
    Function: require_once

    A PHP Error was encountered

    Severity: Warning

    Message: mkdir(): Permission denied

    Filename: libraries/Common.php

    Line Number: 202

    Backtrace:

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
    Line: 202
    Function: mkdir

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
    Line: 236
    Function: getLatexImg

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/views/ver3/inc/view_comment_list.php
    Line: 90
    Function: parseLatexImg

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/views/ver3/inc/view.php
    Line: 343
    Function: view

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
    Line: 558
    Function: view

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
    Line: 315
    Function: require_once

    A PHP Error was encountered

    Severity: Warning

    Message: file_put_contents(/DATA/upload/polymath/latex/328f3047b3d628edf719bb9d54c386d8.gif): failed to open stream: No such file or directory

    Filename: libraries/Common.php

    Line Number: 213

    Backtrace:

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
    Line: 213
    Function: file_put_contents

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/libraries/Common.php
    Line: 236
    Function: getLatexImg

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/views/ver3/inc/view_comment_list.php
    Line: 90
    Function: parseLatexImg

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/views/ver3/inc/view.php
    Line: 343
    Function: view

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/application/controllers/ver3/Contents.php
    Line: 558
    Function: view

    File: /volume1/web/PhpstormProjects/www_polymath_co_kr/index.php
    Line: 315
    Function: require_once

    비밀 댓글이 등록 되었습니다.
    댓글 작성하기 댓글수1
    •  
      김다인(멘토) Lv.15 2021.09.28 18:30

      [해결]

      정말 잘 풀었습니다!! 답장 늦어서 미안해요~!

       

      다인 멘토 드림

      좋아요1
수학동아 - 폴리매스
  • 폴리매스 문제는 과학기술진흥기금 및 복권기금의 재원으로 운영되고, 과학기술정보통신부와 한국과학창의재단의 지원을 받아 수행된 성과물로 우리나라의 과학기술 발전과 사회적 가치 증진에 기여하고 있습니다.

  • ☎문의 02-6749-3911