{"id":886,"date":"2020-06-10T09:39:37","date_gmt":"2020-06-10T09:39:37","guid":{"rendered":"https:\/\/blog.prepbytes.com\/?p=886"},"modified":"2022-03-29T10:01:38","modified_gmt":"2022-03-29T10:01:38","slug":"matrix-and-combination","status":"publish","type":"post","link":"https:\/\/prepbytes.com\/blog\/matrix-and-combination\/","title":{"rendered":"Matrix and combination"},"content":{"rendered":"

\"\"<\/p>\n

CONCEPTS USED:<\/h3>\n
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Recursion<\/p>\n<\/blockquote>\n

DIFFICULTY LEVEL:<\/h3>\n
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Medium<\/p>\n<\/blockquote>\n

PROBLEM STATEMENT(<\/code>SIMPLIFIED)<\/code>:<\/h3>\n
\n

Given a matrix M<\/code>*N<\/code> containing only lowercase english alphabets, your task is to select elements from the first row one by one, and print all the possible combinations downwards. <\/p>\n

Conditions for making Combinations<\/strong>:
\nRule1-<\/code> Every combination starts from the first row of the matrix and proceeds downwards. He may switch columns though.
\nRule2-<\/code> Every combination should have characters equal to the number of rows.
\nRule3-<\/code> A combination can’t have an element from the same row present twice.<\/p>\n<\/blockquote>\n

<\/strong><\/u><\/a><\/p>\n

For Example :<\/h4>\n

\"\"<\/p>\n

Can we use Recursion<\/code> here ?<\/em><\/strong><\/p>\n

\n

Yes, as the problem demands to print all the possible combinations. We can use Recursion<\/code> to find all such combinations.<\/p>\n<\/blockquote>\n

SOLVING APPROACH:<\/h3>\n
\n
    \n
  1. Initialize an empty string Str<\/code> to store our resultant output. <\/li>\n
  2. Start traversing each and every row recursively by incrementing the value of curr row<\/code> by 1<\/code> and keep appending the current character in the Str<\/code>, when we reach the last row, print Str<\/code> and return, as there are no values to process further. <\/li>\n
  3. Similarly all combinations of first row elements will be generated by following step<\/code> 2<\/code>, N<\/code> number of times in a loop.<\/li>\n<\/ol>\n<\/blockquote>\n

    Refer video for Quick Explaination<\/em>:<\/h3>\n

    \"Myself\"<\/a><\/p>\n

    SOLUTIONS:<\/h3>\n

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