N Queens Problem in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare the chessboard size variable.

DSA C

int [1] = 8;

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AN

BboardSize

Csize

Dchessboard

Attempts:

3 left

💡 Hint

Common Mistakes

Using variable names that are not standard or clear like 'boardSize' or 'chessboard'.

The standard variable name for the size of the chessboard in N Queens is N.

2fill in blank

medium

Complete the code to initialize the chessboard array with zeros.

DSA C

int board[[1]][[1]] = {0};

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AboardSize

B8

Csize

DN

Attempts:

3 left

💡 Hint

Common Mistakes

Using a fixed number like 8 instead of the variable N.

Using undefined variables like 'size' or 'boardSize'.

The board size variable N is used to declare the 2D array dimensions.

3fill in blank

hard

Fix the error in the function signature for checking if a queen can be placed.

DSA C

int isSafe(int board[[1]][[1]], int row, int col) {

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Asize

BN

C8

DboardSize

Attempts:

3 left

💡 Hint

Common Mistakes

Using a fixed number like 8 instead of the variable N.

Using undefined variables in the parameter.

The function uses the variable N to represent the board size in the parameter.

4fill in blank

hard

Fill both blanks to complete the loop that checks the left side of the current row for queens.

DSA C

for (int i = 0; i [1] col; i[2]) {
    if (board[row][i] == 1) {
        return 0;
    }
}

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A<

B>

C++

D--

Attempts:

3 left

💡 Hint

Common Mistakes

Using > instead of < in the loop condition.

Using decrement instead of increment.

The loop runs from 0 to col - 1, so the condition is i < col and the increment is i++.

5fill in blank

hard

Fill all three blanks to complete the recursive function call and backtracking step.

DSA C

if (solveNQUtil(board, [1])) {
    return 1;
}
board[row][[2]] = [3]; // Backtrack

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Acol + 1

Bcol

C0

Attempts:

3 left

💡 Hint

Common Mistakes

Not incrementing the column in the recursive call.

Setting the wrong cell to 0 during backtracking.

The recursive call moves to the next column col + 1. The backtracking resets the current cell board[row][col] to 0.