Skip to main content

Strange multidimensional list element changing

I'm trying to make a solution for the n queens problem and I want to make a code writing a number of possible solutions for a n X n board and n queens.

Here is my code:

n = int(input())
piony = [[False for i in range(n)] for j in range(n)]
skosy_lp = [[False for i in range(n)] for j in range(n)]
skosy_pl = [[False for i in range(n)] for j in range(n)]
figury = [-1] * n
counter = 0
layer = 0
#list creating etc. piony list is containing vertical lines occupied by queens, skosy_lp
#is containing lines oblique from left to right, skosy_pl - from right to left.
#this is a backtracking algorithm
#figury list is containing positions of queens. -1 means that the queen isn't placed
while True:
    if layer == -1:
        break
    piony[layer] = piony[layer-1]
    skosy_pl[layer] = skosy_pl[layer-1]
    skosy_pl[layer].append(False)
    skosy_pl[layer].pop(0)
    skosy_lp[layer] = skosy_lp[layer-1]
    skosy_lp[layer].insert(0, False)
    skosy_lp[layer].pop(n)
    figury[layer]+=1
    while figury[layer] < n and (piony[layer][figury[layer]] or skosy_lp[layer][figury[layer]]or skosy_lp[layer][figury[layer]]):
        figury[layer] +=1
    if figury[layer] == n:
        figury[layer] = -1
        piony[layer] = [False] * n
        skosy_pl[layer] = [False] * n
        skosy_lp[layer] = [False] * n
        layer-=1
    else:
        if layer == n-1:
            counter+=1
            layer-=1
        else:
            print(piony)
            #I think there is a bug
            piony[layer][figury[layer]] = True
            skosy_pl[layer][figury[layer]] = True
            skosy_lp[layer][figury[layer]] = True
            layer+=1

When I stop a program in the middle, I discover that when I make piony[layer][figury[layer]] = True for layer = 0 (and figury[layer] = 0) the program is changing piony[0][0] and piony[-1][0].

Can someone tell me why and how to fix it?



source https://stackoverflow.com/questions/76292028/strange-multidimensional-list-element-changing

Labels

Labels:

Comments

Post a Comment

Popular posts from this blog

How to show number of registered users in Laravel based on usertype?

i'm trying to display data from the database in the admin dashboard i used this: <?php use Illuminate\Support\Facades\DB; $users = DB::table('users')->count(); echo $users; ?> and i have successfully get the correct data from the database but what if i want to display a specific data for example in this user table there is "usertype" that specify if the user is normal user or admin i want to user the same code above but to display a specific usertype i tried this: <?php use Illuminate\Support\Facades\DB; $users = DB::table('users')->count()->WHERE usertype =admin; echo $users; ?> but it didn't work, what am i doing wrong? source https://stackoverflow.com/questions/68199726/how-to-show-number-of-registered-users-in-laravel-based-on-usertype
Post a Comment
Read more

Why is my reports service not connecting?

I am trying to pull some data from a Postgres database using Node.js and node-postures but I can't figure out why my service isn't connecting. my routes/index.js file: const express = require('express'); const router = express.Router(); const ordersCountController = require('../controllers/ordersCountController'); const ordersController = require('../controllers/ordersController'); const weeklyReportsController = require('../controllers/weeklyReportsController'); router.get('/orders_count', ordersCountController); router.get('/orders', ordersController); router.get('/weekly_reports', weeklyReportsController); module.exports = router; My controllers/weeklyReportsController.js file: const weeklyReportsService = require('../services/weeklyReportsService'); const weeklyReportsController = async (req, res) => { try { const data = await weeklyReportsService; res.json({data}) console...
Post a Comment
Read more

ValueError: X has 10 features, but LinearRegression is expecting 1 features as input

So, I am trying to predict the model but its throwing error like it has 10 features but it expacts only 1. So I am confused can anyone help me with it? more importantly its not working for me when my friend runs it. It works perfectly fine dose anyone know the reason about it? cv = KFold(n_splits = 10) all_loss = [] for i in range(9): # 1st for loop over polynomial orders poly_order = i X_train = make_polynomial(x, poly_order) loss_at_order = [] # initiate a set to collect loss for CV for train_index, test_index in cv.split(X_train): print('TRAIN:', train_index, 'TEST:', test_index) X_train_cv, X_test_cv = X_train[train_index], X_test[test_index] t_train_cv, t_test_cv = t[train_index], t[test_index] reg.fit(X_train_cv, t_train_cv) loss_at_order.append(np.mean((t_test_cv - reg.predict(X_test_cv))**2)) # collect loss at fold all_loss.append(np.mean(loss_at_order)) # collect loss at order plt.plot(np.log(al...
Post a Comment
Read more