Given a screen with all pixels having one of two colors. Now I will click on a random pixel.
Then that pixel & all the adjacent pixels with same color should change the color to the second color.
adjacent = vertically or horizontally above or blow.
package com.zhuyu_deng.test;
public class Test
{
private static void printMatrix(char[][] a)
{
for (int i = 0; i < a.length; ++i)
{
for (int j = 0; j < a[i].length; ++j)
{
System.out.print(a[i][j] + " ");
}
System.out.println();
}
}
// 关于FloodFill算法的解释
// 以下就是源程序 事实上就是广度搜索
// 但是必须要建立一个所谓的方向数组
private static void floodFill(char[][] a, int x, int y)
{
class Node
{
public Node(int x, int y)
{
this.x = x;
this.y = y;
}
int x;
int y;
}
int px[] = new int[] {0, 0, -1, 1};
int py[] = new int[] {-1, 1, 0, 0};
char orgColor = a[x][y];
char revColor = a[x][y] == 'W' ? 'B' : 'W';
int size = 0;
Node stack[] = new Node[a.length * a[0].length];
stack[size] = new Node(x, y);
while (size >= 0)
{
Node cur = stack[size];
size--;
a[cur.x][cur.y] = revColor;
for (int i = 0; i < 4; ++i)
{
int xx = cur.x + px[i];
int yy = cur.y + py[i];
if (xx >= 0 && xx < a.length && yy >= 0 && yy < a[0].length)
{
if (a[xx][yy] == orgColor)
stack[++size] = new Node(xx, yy);
}
}
}
}
public static void main(String args[])
{
char a[][] = new char[][] { { 'W', 'B', 'W', 'W', 'B', 'W' },
{ 'B', 'B', 'W', 'W', 'B', 'W' },
{ 'W', 'B', 'B', 'B', 'W', 'B' },
{ 'W', 'B', 'W', 'W', 'B', 'B' } };
printMatrix(a);
floodFill(a, 2, 2);
System.out.println();
printMatrix(a);
}
}Edit: Question seem to be not clear to some ppl. Giving an ex:
Given below & clicked on 2nd row, 2nd col
W B W W B W
B B W W B W
W B B B W B
W B W W B B
Covert to
W W W W B W
W W W W B W
W W W W W B
W W W W B B
package com.zhuyu_deng.test;
import java.util.Stack;
public class Test
{
private static void printMatrix(char[][] a)
{
for (int i = 0; i < a.length; ++i)
{
for (int j = 0; j < a[i].length; ++j)
{
System.out.print(a[i][j] + " ");
}
System.out.println();
}
}
private static void floodFill(char[][] a, int x, int y)
{
class Node
{
public Node(int x, int y)
{
this.x = x;
this.y = y;
}
int x;
int y;
}
char orgColor = a[x][y];
char revColor = a[x][y] == 'W' ? 'B' : 'W';
int size = 0;
Node stack[] = new Node[a.length * a[0].length];
stack[size] = new Node(x, y);
while (size >= 0)
{
Node cur = stack[size];
size--;
a[cur.x][cur.y] = revColor;
if (cur.x - 1 >= 0 && orgColor == a[cur.x - 1][cur.y])
{
stack[++size] = (new Node(cur.x-1, cur.y));
}
if (cur.x + 1 < a.length && orgColor == a[cur.x + 1][cur.y])
{
stack[++size] = (new Node(cur.x+1, cur.y));
}
if (cur.y - 1 >= 0 && orgColor == a[cur.x][cur.y - 1])
{
stack[++size] = (new Node(cur.x, cur.y-1));
}
if (cur.y + 1 < a[0].length && orgColor == a[cur.x][cur.y + 1])
{
stack[++size] = (new Node(cur.x, cur.y + 1));
}
}
}
public static void main(String args[])
{
// int[] a = {-2,11,-4,13,-5,-2};
int[][] b = { { 0, -2, -7, 0 }, { 9, 2, -6, 2 }, { -4, 1, -4, 1 },
{ -1, 8, 0, -2 } };
int[][] matrix = { { 2, 3, 4, 1 }, { 1, 1, 3, 9 }, { 2, 2, 3, 1 },
{ 2, 2, 3, 1 } };
char a[][] = new char[][] { { 'W', 'B', 'W', 'W', 'B', 'W' },
{ 'B', 'B', 'W', 'W', 'B', 'W' },
{ 'W', 'B', 'B', 'B', 'W', 'B' },
{ 'W', 'B', 'W', 'W', 'B', 'B' } };
printMatrix(a);
floodFill(a, 2, 2);
System.out.println();
printMatrix(a);
}
}
如文件word.txt内容如下：
what is you name?
my name is zhang san。
要求统计word.txt中出现“is”的次数？
代码如下：
PerWordMapper
package com.hadoop.wordcount;
import java.io.IOException; import java.util.StringTokenizer;
import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Mapper;
public class PerWordMapper extends Mapper<Object, Text, Text, IntWritable> {
public Text keyText = new Text(); public IntWritable intValue = new IntWritable(1); @Override protected void map(Object key, Text value, Context context) throws IOException, InterruptedException { String str = value.toString(); StringTokenizer to = new StringTokenizer(str); while (to.hasMoreTokens()) { String t = to.nextToken(); //此处为判断统计字符串的地方 if(t.equals("is")){ keyText = new Text(t); context.write(keyText, intValue); } } } }
PerWordReducer
package com.hadoop.wordcount;
import java.io.IOException;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;
public class PerWordReducer extends Reducer<Text, IntWritable, Text, IntWritable> {
public IntWritable intValue = new IntWritable(0);
@Override
protected void reduce(Text key, Iterable<IntWritable> value,
Context context)
throws IOException, InterruptedException {
int sum = 0;
while(value.iterator().hasNext()){
sum += value.iterator().next().get();
}
intValue.set(sum);
context.write(key, intValue);
}
}
PerWordCount
package com.hadoop.wordcount;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.GenericOptionsParser;
import com.hadoop.mapreducer.MapperClass;
import com.hadoop.mapreducer.ReducerClass;
import com.hadoop.mapreducer.WordCount;
public class PerWordCount {
public static void main(String[] args) throws IOException, InterruptedException, ClassNotFoundException {
Configuration conf = new Configuration();
String[] otherArgs = new GenericOptionsParser(conf, args).getRemainingArgs();
System.out.println("otherArgs.length:"+otherArgs.length);
if (otherArgs.length != 2) {
System.err.println("Usage: wordcount <in> <out>");
System.exit(2);
}
Job job = new Job(conf, "word count");
job.setJarByClass(PerWordCount.class);
job.setMapperClass(PerWordMapper.class);
job.setCombinerClass(PerWordReducer.class);
job.setReducerClass(PerWordReducer.class);
job.setOutputKeyClass(Text.class);
job.setOutputValueClass(IntWritable.class);
FileInputFormat.addInputPath(job, new Path(otherArgs[0]));
FileOutputFormat.setOutputPath(job, new Path(otherArgs[1]));
System.exit(job.waitForCompletion(true) ? 0 : 1);
}
}
你可以在博主的新页面同样看到这篇文章。
这篇文章我在写第二遍，第一遍写的很详细，可惜因为我很久没用vim了，它生气了，我不小心按错了键，写的好几百行的都没了，这肯定是上天嫌我懒得太久没写了故意来给我这么一下的，好了，不说废话了，下面就是将怎么使用python脚本来在terminal同时更新你在微博和twitter的状态了。
先说微博
首先第一步我们都是要先申请一个开发者的帐号的，关于具体的一些细节可以看看这里，里面讲了授权使用的方式和原理，像我使用的是第三方的SDK，就只是简单的看了一下，没有太深入的了解，不过想要开发SDK的同学还是可以好好研究的。
下面就是代码了：
from weibo import APIClient
from re import split
import urllib,httplib
APP_KEY = '1******671' #youre app key
APP_SECRET = 'e623c*************bfa30b23' #youre app secret
# callback url, your must set this URL in your "my application->appInfos-> advanced info"
CALLBACK_URL = 'http://ww****shore.com'
ACCOUNT = 'bo******@gmail.com'#your email address
PASSWORD = '*********' #your pw
#for getting the code contained in the callback url
def get_code(url):
conn = httplib.HTTPSConnection('api.weibo.com')
postdata = urllib.urlencode ({'client_id':APP_KEY,'response_type':'code','redirect_uri':CALLBACK_URL,'action':'submit','userId':ACCOUNT,'passwd':PASSWORD,'isLoginSina':0,'from':'','regCallback':'','state':'','ticket':'','withOfficalFlag':0})
conn.request('POST','/oauth2/authorize',postdata,{'Referer':url,'Content-Type': 'application/x-www-form-urlencoded'})
res = conn.getresponse()
location = res.getheader('location')
code = location.split('=')[1]
conn.close()
return code
def post_weibo(post_contents):
print "weibo posting..."
#for getting the authorize url
client = APIClient(app_key=APP_KEY, app_secret=APP_SECRET, redirect_uri=CALLBACK_URL)
url = client.get_authorize_url()
code = get_code(url)
r = client.request_access_token(code)
access_token = r.access_token # The token return by sina
expires_in = r.expires_in
#save the access token
client.set_access_token(access_token, expires_in)
results = client.post.statuses__update(status=post_contents)
return results
从上面的代码中，有一点需要注意一下那就是，get_code(),这个函数是获取了授权码，在本来的SDK中是没有这一步的，但是少了这一步我们就需要人工的在浏览区的网页上点击连接授权，而我却只想在命令行里面完成所有的事情，所以才有了这个函数，函数中是使用了httplib包模拟了web请求，并且处理了返回的信息，从而获取到了授权码。
之所以没有实现人人网，也是因为授权码的问题，可以看看人人网的开发者文档，授权方式和微博相似，不同就在于不能够我们自己通过代码发送请求来获取授权码，这也就解释了为什么人人网推荐的python SDK都是挂在GAE上的，应该就是因为这个原因，需要我们亲自在网页上进行授权，也正式因为此，我才放弃了人人。其实他们有一个用户名密码端的服务，不过需要填表申请，表我是填了，不过后面就没有消息了，我相信如果我申请成功了，那么就可以使用和微博相同的方式了获取授权码从而获取调用API的tokens了。还是希望有聪明才智的哪位大牛搞成功了，看到这篇文章可以教一下我。
再说Twitter
看了推特的文档才知道美帝的东西就是好，他们用授权方式要更加先进，减少了授权了步骤，使用REST API也使开发者更方便的开发SDK，所以推特的SDK明显要好很多。最受欢迎的tweepy是我的第一次尝试，失败原因至今不是很明确，但因该和我使用的代理有关系，也就是说在国内使用代理上推特和Fb的要注意下，使用tweepy可能会带来的失败。除此之外，还有一点提醒大家需要注意，就是申请的twitter的App是有访问级别的限制的，默认是read only，可以自己改成 read&write 或者 read, write & direct message 都是可以的。
后来我选择的