Leuke vrijdagmiddagklus
Regel 88 en 95 is de optimalisatie (kun je // commenten om verschil te zien). In het voorbeeld is dat een winst van 63 versus 130 lookups.
De "3" in de aanroep (onload) is de block size. Heb het getest met 3, 4, 5 en 6 (alhoewel 4 en 6 dubieuze centers hebben...).
Het kan vast nog wel beter, ik doe bijvoorbeeld niets recursief. Toch denk ik dat de performance wel in orde is.
HTML:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
| <!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Grid availability</title>
<style type="text/css">
td {
height:40px;
width:40px;
color:white;
vertical-align:middle;
text-align:center;
border:2px solid white;
}
</style>
<script type="text/javascript">
Array.min = function( array ){
return Math.min.apply( Math, array );
};
var app = {};
app.findSweetSpot = function(iBlockSize) {
var iStart = Math.ceil(iBlockSize / 2) - iBlockSize;
var iNumberOfLookups = 0, iNumberOfCellsAnalyzed = 0;
var oGrid = document.getElementById('grid');
var aGrid = [], aGridCache = [], aRows = oGrid.getElementsByTagName('tr'), aCells = [];
// Populate array (representing table/grid in DOM)
var i, j, k, l;
for(i = 0, iLength = aRows.length; i < iLength; i++) {
aCells[i] = aRows[i].getElementsByTagName('td');
aGrid[i] = [];
for(j = 0, jLength = aCells[i].length; j < jLength; j++) {
aCells[i][j].style.backgroundColor = 'orange';
aGrid[i][j] = aCells[i][j].innerHTML === ''; // The evaluation for "available" cell
}
}
// Lookup surrounding array elements (depending on block size)
var isBlockAvailable = function(x, y) {
var m, n;
for(m = 0; m < iBlockSize; m++) {
for(n = 0; n < iBlockSize; n++) {
xm = x + iStart + m;
yn = y + iStart + n
// Debug stuff
console.info('Analyzing', 'cell:', x+1, y+1, 'blockcell:', m+1, n+1, 'avail:', aGrid[xm][yn]);
aCells[xm][yn].innerHTML = aCells[xm][yn].innerHTML && aCells[xm][yn].innerHTML !== 'X' ? parseInt(aCells[xm][yn].innerHTML) + 1 : 1;
iNumberOfLookups++;
if(!aCells[xm][yn]._analyzed) {
iNumberOfCellsAnalyzed++;
aCells[xm][yn]._analyzed = true;
aCells[xm][yn].style.backgroundColor = 'blue';
}
// End debug stuff
if(aGrid[xm][yn] === false) {
return [false, m, n];
}
}
}
return [true];
};
// Walk rows and columns
// Use center cell as basis
// Skip outer rows and columns based on block size
// Optimize route by skipping rows/columns
var searchAvailableBlock = function(aGrid) {
var aRow, aOptimizer, aOptimizerY = [];
for(k = 0 - iStart, kLength = aGrid.length + iStart; k < kLength; k++) {
aRow = aGrid[k];
for(l = 0 - iStart, lLength = aRow.length + iStart; l < lLength; l++) {
console.group('Lookup availability for', 'row', k+1, 'column', l+1);
aOptimizer = isBlockAvailable(k, l);
if(aOptimizer[0]) {
console.groupEnd();
return [k, l];
} else {
console.info('Skipping ' + aOptimizer[2] + ' columns');
l += aOptimizer[2];
aOptimizerY.push(aOptimizer[1]);
}
console.groupEnd();
}
if(aOptimizerY.length > 0) {
console.info('Skipping ' + Array.min(aOptimizerY) + ' rows')
k += Array.min(aOptimizerY);
aOptimizerY = [];
}
}
};
var aResult = searchAvailableBlock(aGrid);
if(aResult) {
aCells[aResult[0]][aResult[1]].style.backgroundColor = 'red';
}
console.info('Number of cells analyzed: ' + iNumberOfCellsAnalyzed)
console.info('Number of total cell lookups: ' + iNumberOfLookups)
};
</script>
</head>
<body onload="app.findSweetSpot(3);">
<table id="grid">
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td style="border-color:red;">X</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td style="border-color:red;">X</td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td style="border-color:red;">X</td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td style="border-color:red;">X</td>
<td></td>
</tr>
<tr>
<td></td>
<td style="border-color:red;">X</td>
<td></td>
<td style="border-color:red;">X</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td style="border-color:red;">X</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
</table>
</body>
</html> |
PS Nog nooit was "Zen coding" in Textmate zo nuttig: met "table#grid>tr*9>td*9" en Cmd-e stond de tabel er.
/u/12612/crop65b399f21bc43_cropped.png?f=community)
:strip_exif()/u/27216/bosmonster_dropdown.gif?f=community)
/u/7685/ruinmytune-60x60.png?f=community)
:strip_icc():strip_exif()/u/102743/me_green_70.jpg?f=community)