Spies, Revised

Problem Statement :

Two spies in a grid will have their covers blown if:

1 . They are both in the same row.
2. They are both in the same column.
3. They can see each other diagonally (i.e., lie in a line inclined 45° or 135° to the base of the grid).

The level of danger is now increased! In addition to the conditions above, no 3 spies may lie in any straight line. This line need not be aligned 45° or 135° to the base of grid.

Write a program in the language of your choice to place N spies (one spy per row) on an N x N grid without blowing anyone's cover. Your program must then print the following 2 lines describing a valid configuration:

1. The value of N.
2. A space-separated list of 1-indexed column numbers, where each value i is the column number of the spy in row i (where 1  <=  i  <=  N ).

Solve this problem for N as large as possible, up to (and including) 999.

Note: Run and Custom Input are not available for this challenge; you must click Submit Code for your submission to be scored. Your score for this challenge will always be the maximum value scored by any of your submissions.


In the examples below, S denotes a spy and * denotes an empty cell.

Input Format

There is no input for this challenge.


N is odd.
N  <  1000  (Do not submit for any value of N larger than 999 )

Output Format

Print the following 2 lines of output:

1. The first line should be a single integer denoting the value of N.
2 .The second line should contain a space-separated list of integers . Each integer i (where 1 < i  <=  N) should be the 1-indexed column number where the spy in row i is located.

Solution :


                            Solution in C :

In   Python3  : ( Problem has Ambiguity )

import random

def check(a):
    for k in final_list:
        for i in range(n):
            for j in range(n):
                if i==j:
                   if [x+i,y+j] in final_list:
                        return 0
                   if [x-i,y-j] in final_list:
                       return 0
                elif [x+i,y+j] in final_list:
                    if len(chk1)>2:
                        return 0
                elif [x-i,y-j] in final_list:
                    if len(chk2)>2:
                        return 0

for i in range(n):
def number_generator():
        r = random.choice(list_of_numbers)
        c = random.choice(list_of_numbers)
        if r not in rows and c not in colomns:
        if len(final_list)==n:
    if not check(1):

        for i in final_list:
            new_list.append(i[0]*n + (i[1]+1))
        for i in new_list:
            print(i, end=" ")

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