Generating N-Queens possible solution sturvs.

N-Queens.py

def placequeens(arr, r):
    n = len(arr)
    res = []
    if r == n:
    # Print solutions
        print(arr)
    else:
        for j in range(0, n):
            legal = True
            for i in range(0, r):
                if (arr[i] == j) or (arr[i] == j + r - i) or (arr[i] == j - r + i):
                    legal = False
            if legal:
                arr[r] = j
                res.append(arr)
                placequeens(arr, r+1)
    return len(res) # return length of available solutions.. returns 8 for an 8 * 8 board sha.

print(placequeens([0,0,0,0,0,0,0,0], 0))
print(placequeens([0,0,0,0], 0))