N-queens problem: Difference between revisions

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@@ Line 803: / Line 803: @@
 =={{header|D}}==
 From the C solution.
-<lang d>import std.stdio: write, writeln, writefln;
+<lang d>import std.stdio: write, writeln;
 enum int SIDE = 8;
-int[SIDE] b;
+int[SIDE] board;
-bool unsafe(int y) {
+nothrow bool unsafe(int y) {
-    int x = b[y];
+    immutable int x = board[y];
     foreach (i; 1 .. y+1) {
-        int t = b[y - i];
+        int t = board[y - i];
         if ((t == x) || (t == x - i) || (t == x + i))
             return true;
@@ Line 819: / Line 819: @@
 }
-void show_board() {
+void showBoard() {
     static int s = 0;
-    writefln("\nSolution #%d", ++s);
+    writeln("\nSolution #", ++s);
     foreach (y; 0 .. SIDE) {
         foreach (x; 0 .. SIDE)
-            write(b[y] == x ? "|Q" : "|_");
+            write(board[y] == x ? '*' : '.');
-        writeln("|");
+        writeln();
     }
 }
@@ Line 831: / Line 831: @@
 void main() {
     int y = 0;
-    b[0] = -1;
+    board[0] = -1;
     while (y >= 0) {
         do {
-            b[y]++;
+            board[y]++;
-        } while (b[y] < SIDE && unsafe(y));
+        } while (board[y] < SIDE && unsafe(y));
-        if (b[y] < SIDE) {
-            if (y < (SIDE - 1)) {
+        if (board[y] < SIDE) {
-                b[++y] = -1;
+            if (y < (SIDE - 1))
-            } else {
+                board[++y] = -1;
-                show_board();
+            else
-            }
+                showBoard();
-        } else {
+        } else
             y--;
-        }
     }
 }</lang>
+===Brute force version===
-Brute force version
 <lang d>auto nqueens(int base) {
     int total = base * base;