2010を1~9の四則演算で表す
/**
* Copyright uwi ( http://wonderfl.net/user/uwi )
* MIT License ( http://www.opensource.org/licenses/mit-license.php )
* Downloaded from: http://wonderfl.net/c/m1wp
*/
package {
import flash.display.Sprite;
import flash.text.TextField;
import flash.utils.getTimer;
import flash.events.*;
import com.bit101.components.*;
public class Test extends Sprite {
private var _tf : TextField;
private const OPES : Array = ["+", "-", "*", "/"];
private var _ct : uint;
private var _p : Array = [0, 1, 2, 3, 4, 5, 6, 7]; // 順列用
private var _set : Object = {};
private const N : int = 2010;
private const STEP : uint = 10;
// ネタ
private var _pb : Meter;
private var _il : IndicatorLight;
public function Test() {
_tf = new TextField();
_tf.width = 465;
_tf.height = 465;
addChild(_tf);
_pb = new Meter(this, 250, 0, "Progress");
_pb.maximum = 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1;
_il = new IndicatorLight(this, 250, 100, 0xffff00, "Finished");
_il.isLit = false;
_ct = 0;
addEventListener(Event.ENTER_FRAME, onEnterFrame);
}
private var _step : uint = 0;
private function onEnterFrame(e : Event) : void
{
for(var i : uint = 0;i < STEP;i++){
if(process()){
removeEventListener(Event.ENTER_FRAME, onEnterFrame);
tr(_ct);
_pb.value = _pb.maximum;
_il.isLit = true;
return;
}
}
_step += STEP;
_pb.value = _step;
}
private function process() : Boolean
{
var i : uint, j : uint, k : int;
var inds : Array = _p.concat(); // 結合後インデックス
var cur : Array = [[1], [2], [3], [4], [5], [6], [7], [8], [9]];
var hist : Array = []; // 逆算用履歴
for(i = 0;i < inds.length;i++){
// 結合後のインデックスに直す
for(j = i + 1;j < inds.length;j++){
if(inds[j] > inds[i])inds[j]--;
}
// 隣同士を結合させていく
var next : Array = [];
for each(var a : Number in cur[inds[i]]){
for each(var b : Number in cur[inds[i]+1]){
// next.push(a+b, a-b, a*b);
next.push(a+b, a-b, a*b, a/b);
// next.push(a+b, a-b, a*b, 10*a+b);
}
}
hist.push(cur[inds[i]+1].length);
cur.splice(inds[i], 2, next);
}
for(j = 0;j < cur[0].length;j++){
if(cur[0][j] == N){
// 逆算して演算子を割り出す
var q : Array = new Array(9);
var c : Array = [j];
for(k = inds.length - 1;k >= 0;k--){
q[k] = c[inds[k]] % 4;
var n : uint = c[inds[k]] / 4;
c.splice(inds[k], 1, uint(n / hist[k]), n % hist[k]);
}
// 数式をくっつける
var strs : Array = ["1", "2", "3", "4", "5", "6", "7", "8", "9"];
var methods : Array = [-1, -1, -1, -1, -1, -1, -1, -1]; // 直前の演算子
for(k = 0;k < inds.length;k++){
if(q[k] >= 1){
// +以外でくっつけるとき、くっつけようとしている要素が+-で結合している場合はカッコで囲む
if(q[k] >= 2 && methods[inds[k]] >= 0 && methods[inds[k]] <= 1){
strs[inds[k]] = "(" + strs[inds[k]] + ")";
}
if(methods[inds[k]+1] >= 0 && methods[inds[k]+1] <= 1){
strs[inds[k]+1] = "(" + strs[inds[k]+1] + ")";
}
}
var nexstr : String = strs[inds[k]] + OPES[q[k]] + strs[inds[k]+1];
strs.splice(inds[k], 2, nexstr);
methods.splice(inds[k], 2, q[k]);
}
// 既出か確認
if(!_set[strs[0]]){
_set[strs[0]] = 1;
tr(strs[0]);
_ct++;
}
}
}
return nextPermutation(_p) == null;
}
// 次の順列を出す
private static function nextPermutation(src : Array) : Array
{
for(var i : int = src.length - 2;i >= 0 && src[i] > src[i + 1];i--);
if(i == -1)return null;
for(var j : int = i + 1;j < src.length && src[i] < src[j];j++);
var d : int;
d = src[i]; src[i] = src[j - 1]; src[j - 1] = d;
for(var p : int = i + 1, q : int = src.length - 1;p < q;p++, q--){
d = src[p]; src[p] = src[q]; src[q] = d;
}
return src;
}
private function tr(...o : Array) : void
{
_tf.appendText(o + "\n");
_tf.scrollV = _tf.maxScrollV;
}
}
}