InfyTQ Python Coding Questions & Answer 2022 - Four in a line

 InfyTQ  Python Coding Questions & Answer 2022

Four in a line

Problem Statement -: 

Given a m x n matrix inmatrix of positive integers, print an integer outnum based on the below logic: 

Identify all possible sets in inmatrix that contain at least four consecutive elements of the same value val, either horizontally, vertically, or diagonally 

If only one set of consecutive elements is identified, store the value val in outnum 

If more than one set of consecutive elements is identified, find the smallest value and store it in outnum 

If no set of four consecutive elements of the same value is identified either horizontally, vertically, or diagonally, print -1 

Assumption: 

m and n will be greater than 3 

Input format: 

First line will contain number of rows m of inmatrix

The next m lines will contain the elements of inmatrix. Each line will have n elements separated by space.

Read the input from the standard input stream. 

Output format: 

Print outnum to the standard output stream. 

Sample Input 1
5
0 1 6 8 8 9
5 6 1 6 8 9 
6 5 6 1 1 9
1 6 6 1 1 9
6 3 3 3 3 9

Sample Output 1
1

Explanation 1
Following elements are present consecutively at least four times: Element 3 horizontally in the 5th row. Element 1 diagonally starting from the 2nd column in the first row. Element 6 diagonally starting from the 4th column in the second row. Element 9 vertically in the 6th column. As element 1 is the smallest value of the four identified sets of consecutive values, the output is 1  

Sample input 2
5
0 1 6 8 6 0
5 5 2 1 8 2
6 5 6 1 1 9
1 5 6 1 4 0
3 7 3 3 4 0 

Sample Output 2
-1

Explanation 2
Here there are no sets of four consecutive elements of the same value either horizontally, vertically,or diagonally  hence output is -1

Program :

r=int(input("Number of Rows : "))

a=[]

for i in range(r):

 b=list(map(int,input().split()))

 a.append(b)

 

c=len(a[0])

ans=set()

i=0

while i<r:

 j=0

 while j<(c-3):

  if a[i][j]==a[i][j+1] and a[i][j]==a[i][j+2] and a[i][j]==a[i][j+3]:

   ans.add(a[i][j])

   j+=4

 

  else:

   j+=1

 

 i+=1

 

j=0

while j<c:

 i=0

 while i<(r-3):

  if a[i][j]==a[i+1][j] and a[i][j]==a[i+2][j] and a[i][j]==a[i+3][j]:

   ans.add(a[i][j])

   i+=4

 

  else:

   i+=1

 

 j+=1

 

for i in range(r):

 i1=i

 j=0

 while (i1+3)<r and (j+3)<c:

  if a[i1][j]==a[i1+1][j+1] and a[i1][j]==a[i1+2][j+2] and a[i1][j]==a[i1+3][j+3]:

    i1+=4

    j+=4

    ans.add(a[i1][j])

 

  else:

   i1+=1

   j+=1

 

for j1 in range(1,c):

 j=j1

 i1=0

 while (i1+3)<r and (j+3)<c:

  if a[i1][j]==a[i1+1][j+1] and a[i1][j]==a[i1+2][j+2] and a[i1][j]==a[i1+3][j+3]:

    ans.add(a[i1][j])

    i1+=4

    j+=4

 

  else:

   i1+=1

   j+=1

 

for i in range(r):

 i1=i

 j=(c-1)

 while (i1+3)<r and (j-3)>=0:

  if a[i1][j]==a[i1+1][j-1] and a[i1][j]==a[i1+2][j-2] and a[i1][j]==a[i1+3][j-3]:

    i1+=4

    j-=4

    ans.add(a[i1][j])

 

  else:

   i1+=1

   j-=1

 

for j1 in range(c-2,-1,-1):

 j=j1

 i1=0

 while (i1+3)<r and (j-3)>=0:

  if a[i1][j]==a[i1+1][j-1] and a[i1][j]==a[i1+2][j-2] and a[i1][j]==a[i1+3][j-3]:

    ans.add(a[i1][j])

    i1+=4

    j-=4

 

  else:

   i1+=1

   j-=1

 

if len(ans)>=1:

 print(min(ans))

 

else:

 print(-1)

 

for execution and output so check the video :