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
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
#include "kollib.h"
#include "message.h"
#include <iostream>
#include <cmath>
#include <queue>
#include <set>
#include <vector>
#include <map>
#include <unordered_set>

using namespace std;
typedef long long LL;

bool isManager = false;
int nodeId = 0;
int nodesCount = 0;
int queriesCount = 0;
LL studentsCount = 0;
LL packetSize = 0;

struct JobRequest
{
	int start;
	int start_next;
};

bool operator<(const JobRequest& l, const JobRequest& r) {
     return (l.start<r.start || (l.start==r.start && l.start_next<r.start_next));
}

struct JobResult
{
	int start;
	int start_next;
	int stop_previous;
	int stop;
	int time;
};


enum MessageTypes
{
	MessageFinished = 0,
	MessageDoWork = 1,
	MessageWorkDone = 2
};

struct Message
{
public:
	int nodeId;
	int type;
	JobRequest jobRequest;
	JobResult jobResult;
};

Message receiveMessage(int raw_id)
{
	int id = Receive(raw_id);
	Message m;
	m.nodeId = GetInt(id);
	m.type = GetInt(id);
	if (m.type == MessageWorkDone)
	{
		m.jobResult.start = GetInt(id);
		m.jobResult.start_next = GetInt(id);
		m.jobResult.stop_previous = GetInt(id);
		m.jobResult.stop = GetInt(id);
		m.jobResult.time = GetInt(id);
	}
	else if (m.type == MessageDoWork)
	{
		m.jobRequest.start = GetInt(id);
		m.jobRequest.start_next = GetInt(id);
	}
	fprintf(stderr, "[%d<-%d] Received: %d\n", nodeId, id, m.type); 
	return m;
}

void sendMessage(int id, const Message& m)
{
	PutInt(id, nodeId);
	PutInt(id, m.type);
	if (m.type == MessageWorkDone)
	{
		PutInt(id, m.jobResult.start);
		PutInt(id, m.jobResult.start_next);
		PutInt(id, m.jobResult.stop_previous);
		PutInt(id, m.jobResult.stop);
		PutInt(id, m.jobResult.time);
	}
	else if (m.type == MessageDoWork)
	{
		PutInt(id, m.jobRequest.start);
		PutInt(id, m.jobRequest.start_next);
	}
	Send(id);
	fprintf(stderr, "[%d->%d] Sending: %d\n", nodeId, id, m.type); 
//	fprintf(stderr, "[%d->%d] Sending: %d, qid: %d, from: %d, to: %d, time: %d\n", nodeId, id, m.type, m.job.queryId, m.job.from, m.job.to, m.job.time); 
}


JobResult doTheWork(JobRequest request, unordered_set<int>& points)
{
	int counter = 0;
	int previous = request.start;
	int current = request.start_next;
	while (true)
	{
		++counter;
		if (points.count(current) > 0)
		{
			// work done
			JobResult result;
			result.start = request.start;
			result.start_next = request.start_next;
			result.stop_previous = previous;
			result.stop = current;
			result.time = counter;
			return result;
		}
		int n = FirstNeighbor(current);
		if (n == previous)
		{
			n = SecondNeighbor(current);
		}
		
		previous = current;
		current = n;
	}
}

void slave()
{
	unordered_set<int> points;
  for (int i = 1; i <= queriesCount; ++i) {
		int from = QueryFrom(i);
		int to = QueryTo(i);
		points.insert(from);
		points.insert(to);
	}
	fprintf(stderr, "[%d] Entering message loop...\n", nodeId); 
	
	while (true)
	{
		Message request = receiveMessage(0);
		if (request.type == MessageFinished)
			return;
	
		// do work
		Message response;
		response.nodeId = nodeId;
		response.type = MessageWorkDone;
		response.jobResult = doTheWork(request.jobRequest, points);
		sendMessage(0, response);
	}
}

void initializeJobs(set<JobRequest>& jobs, map<int, int>& results, set<int>& remaining)
{
  for (int i = 1; i <= queriesCount; ++i) {
		int from = QueryFrom(i);
		int to = QueryTo(i);
    if (from == to)
		{
			results[i] = 0;
			remaining.erase(i);
		}
		
		JobRequest job;
		job.start = from;
		job.start_next = FirstNeighbor(from);
		jobs.insert(job);
		
		job.start = from;
		job.start_next = SecondNeighbor(from);
		jobs.insert(job);
			
		job.start = to;
		job.start_next = FirstNeighbor(to);
		jobs.insert(job);
		
		job.start = to;
		job.start_next = SecondNeighbor(to);
		jobs.insert(job);
	}
}
typedef set<int>::iterator siit;

void update_fragments(map<JobRequest, JobResult>& fragments, JobResult result)
{
	JobRequest jr;
	jr.start = result.start;
	jr.start_next = result.start_next;
	fragments[jr] = result;
	
	JobResult result2;
	result2.start = result.stop;
	result2.start_next = result.stop_previous;
	result2.stop_previous = result.start_next;
	result2.stop = result.start;
	result2.time = result.time;
	jr.start = result2.start;
	jr.start_next = result2.start_next;
	fragments[jr] = result2;
}

void check_paths(int queryId, map<JobRequest, JobResult>& fragments, JobRequest jr, int to, map<int, int>& results, set<int>& found)
{
	int count = 0;
	map<JobRequest, JobResult>::iterator itFragments;
	while ((itFragments = fragments.find(jr)) != fragments.end())
	{
		
		JobResult result = itFragments->second;
//					fprintf(stderr, "fragment %d, %d, %d, %d; %d->%d\n", result.start, result.start_next, result.stop_previous, result.stop, from, to);
		count += result.time;
		if (result.stop == to)
		{
//						fprintf(stderr, "fragment found %d->%d\n", queryId, count);
			results[queryId] = min((LL)count, (LL)studentsCount - count);
			found.insert(queryId);
			break;
		}
		jr.start = result.stop;
		jr.start_next = FirstNeighbor(jr.start);
		if (jr.start_next == result.stop_previous)
		{
			jr.start_next = SecondNeighbor(jr.start);
		}
	}
	
}
void master()
{
	set<JobRequest> jobs;
	map<int, int> results;
	set<int> remaining;
	set<int> availableNodes;
	set<int> workingNodes;
	for (int i = 1; i < nodesCount; ++i)
	{
		availableNodes.insert(i);
	}
	for(int i = 1; i <= queriesCount; ++i)
	{
		remaining.insert(i);
	}
	initializeJobs(jobs, results, remaining);
	
	map<JobRequest, JobResult> fragments;
	
	// in loop:
	// - send job to all children
	// - do some work too
	// - receive results from all children
	fprintf(stderr, "[%d] Entering main loop...\n", nodeId); 
	
	while (jobs.size() > 0 || workingNodes.size() > 0)
//	while (remaining.size() > 0)
	{
		// allocate unprocessed jobs to available nodes
		while (availableNodes.size() > 0)
		{
//			fprintf(stderr, "[%d] job size %lu\n", nodeId, jobs.size());
			set<JobRequest>::iterator itJob = jobs.begin();
			if (itJob == jobs.end())
			{
				break;
			}
			JobRequest job = *itJob;
			jobs.erase(itJob);
			if (fragments.find(job) == fragments.end())
			{
				siit itNode = availableNodes.begin();
				int id = *itNode;
				availableNodes.erase(id);
				workingNodes.insert(id);
				Message m;
				m.type = MessageDoWork;
				m.jobRequest = job;
				sendMessage(id, m);
			}
		}
		
		if (workingNodes.size() > 0)
		{
			Message m = receiveMessage(-1);
			workingNodes.erase(m.nodeId);
			availableNodes.insert(m.nodeId);
			update_fragments(fragments, m.jobResult);
//			fprintf(stderr, "fragments count %lu, remaining %lu\n", fragments.size(), remaining.size());
			
			// check if any path is full
			set<int> found;
			for(siit itQuery = remaining.begin(); itQuery != remaining.end(); ++itQuery)
			{
				int queryId = *itQuery;
				int from = QueryFrom(queryId);
				int to = QueryTo(queryId);
				
				JobRequest jr;
				jr.start = from;
				jr.start_next = FirstNeighbor(from);
				
				check_paths(queryId, fragments, jr, to, results, found);
				jr.start_next = SecondNeighbor(from);
				check_paths(queryId, fragments, jr, to, results, found);
			}
			for(siit itQuery = found.begin(); itQuery != found.end(); ++itQuery)
			{
				remaining.erase(*itQuery);
			}
		}
	}
	
	fprintf(stderr, "killing workers...\n");
	for(siit itNode = availableNodes.begin(); itNode != availableNodes.end(); ++itNode)
	{
		Message m;
		m.type = MessageFinished;
		sendMessage(*itNode, m);
	}
	
//	fprintf(stderr, "result size %lu\n", results.size());
	for(int i = 1; i <= queriesCount; ++i)
	{
//		fprintf(stderr, "answer %d -> %d\n", i, results[i]);
		printf("%d\n", results[i]);
	}
}

int main() {
	nodeId = MyNodeId();
	nodesCount = NumberOfNodes();
	studentsCount = NumberOfStudents();
	queriesCount = NumberOfQueries();
	packetSize = max(10000LL, studentsCount * queriesCount / (100 * nodesCount));
	fprintf(stderr, "NodeId: %d, Nodes: %d, Students: %lld, Queries: %d, packet: %lld\n", nodeId, nodesCount, studentsCount, queriesCount, packetSize);

	if (nodeId == 0)
		master();
	else
		slave();
  return 0;
}