N-queens minimum and knights and bishops: Difference between revisions

Content added Content deleted
(→‎{{header|Go}}: Improvement for knights.)
(→‎{{header|Wren}}: Incorporated latest Go improvement.)
Line 1,629: Line 1,629:
This was originally based on the Java code [https://www.geeksforgeeks.org/minimum-queens-required-to-cover-all-the-squares-of-a-chess-board/ here] which uses a backtracking algorithm and which I extended to deal with bishops and knights as well as queens when translating to Wren. I then used the more efficient way for checking the diagonals described [https://www.geeksforgeeks.org/n-queen-problem-using-branch-and-bound/ here] and have now incorporated the improvements made to the Go version.
This was originally based on the Java code [https://www.geeksforgeeks.org/minimum-queens-required-to-cover-all-the-squares-of-a-chess-board/ here] which uses a backtracking algorithm and which I extended to deal with bishops and knights as well as queens when translating to Wren. I then used the more efficient way for checking the diagonals described [https://www.geeksforgeeks.org/n-queen-problem-using-branch-and-bound/ here] and have now incorporated the improvements made to the Go version.


Although far quicker than it was originally (it now gets to 7 knights in less than a minute), it struggles after that and needs north of 26 minutes to get to 10.
Although far quicker than it was originally (it now gets to 7 knights in less than a minute), it struggles after that and needs north of 21 minutes to get to 10.
<lang ecmascript>import "./fmt" for Fmt
<lang ecmascript>import "./fmt" for Fmt


Line 1,709: Line 1,709:
}
}
if (countSoFar <= maxCount) {
if (countSoFar <= maxCount) {
var si = (piece == "K") ? 0 : ti
var si = (piece == "K") ? (ti-2).max(0) : ti
var sj = (piece == "K") ? 0 : tj
var sj = (piece == "K") ? (tj-2).max(0) : tj
for (i in si...n) {
for (i in si...n) {
for (j in sj...n) {
for (j in sj...n) {
Line 1,858: Line 1,858:
. . . . . . . . . .
. . . . . . . . . .


Took 1583.020941 seconds.
Took 1276.522608 seconds.
</pre>
</pre>
Retrieved from "https://rosettacode.org/wiki/N-queens_minimum_and_knights_and_bishops"