Added cleaner resolution for level-2 n_queens

level-2/n_queens/n_queens_clean.c

@@ -1,93 +1,68 @@
-#include <unistd.h>
-#include <stdlib.h>
 #include <stdio.h>
+#include <stdlib.h>
 
-void ft_putchar(char c)
+int *board;
+int target;
+
+int ft_abs(int value)
 {
-	write(1, &c, 1);
+    if (value < 0)
+        return (value * -1);
+    return (value);
 }
 
-void ft_putnbr(int n)
+void print_board()
 {
-	if (n >= 10)
-		ft_putnbr(n / 10);
-	ft_putchar((n % 10) + '0');
+    int i = 0;
+    while (i < target)
+    {
+        if (i == 0)
+            fprintf(stdout, "%i", board[i]);
+        else
+            fprintf(stdout, " %i", board[i]);
+        i++;
+    }
+    fprintf(stdout,"\n");
 }
 
-void print_solution(int *board, int n)
+int is_safe(int row, int col)
 {
-	int i = 0;
-	while (i < n)
-	{
-		ft_putnbr(board[i]);
-		if (i < n - 1)
-			ft_putchar(' ');
-		i++;
-	}
-	ft_putchar('\n');
+    int c = 0;
+    while (c < col)
+    {
+        if (board[c] == row)
+            return (0);
+        if (ft_abs(board[c] - row) == ft_abs(col -c))
+            return (0);
+        c++;
+    }
+    return (1);
 }
 
-int	ft_abs(int nbr)
+void solve(int col)
 {
-	if (nbr < 0)
-		return (nbr * -1);
-	else
-		return (nbr);
+    if (col == target)
+        return (print_board());
+
+    int row = 0;
+    while (row < target)
+    {
+        if (is_safe(row, col))
+        {
+            board[col] = row;
+            solve(col + 1);
+        }
+        row++;
+    }
 }
 
-int is_safe(int *board, int n, int row, int col)
+int main(int ac, char **av)
 {
-	int i;
-
-	i = 0;
-	(void)n;
-	while (i < col)
-	{
-		if (board[i] == row)
-			return (0);
-		if (ft_abs(board[i] - row) == (col - i))
-			return (0);
-		i++;
-	}
-	return (1);
-}
-
-void solve(int *board, int n, int col)
-{
-	if (col == n)
-		return(print_solution(board, n));
-
-	int row = 0;
-	while (row < n)
-	{
-		if (is_safe(board, n, row, col))
-		{
-			board[col] = row;
-			solve(board, n, col + 1);
-		}
-		row++;
-	}
-}
-
-int main(int argc, char **argv)
-{
-	int *board;
-	int n;
-
-	if (argc != 2)
-		return (fprintf(stderr, "Usage: %s n\n", argv[0]), 1);
-
-	n = atoi(argv[1]);
-	if (n <= 0)
-		return (0); 
-	
-	board = (int *)malloc(sizeof(int) * n);
-	if (!board)
-	{
-		fprintf(stderr, "Memory allocation failed\n");
-		return (1);
-	}
-	solve(board, n, 0);
-	free(board);
-	return (0);
+    if (ac != 2)
+        return (1);
+    target = atoi(av[1]);
+    board = (int *)calloc(target, sizeof(int));
+    solve(0);
+    free(board);
+    return (0);
 }