POJ 3436 ACM Computer Factory

#include <iostream>
#include <cstdlib>
#include <cstring>
#include <vector>
#include <algorithm>
#include <queue>
#include <climits>
#include <utility>

const int MaxCount = 64;
struct Edge
{
	Edge(int _t, int _c, int _r)
		:to(_t),cap(_c),rev(_r)
	{

	}
	int to, cap, rev;
};

std::vector<Edge> G[2*MaxCount+2];
int level[MaxCount];
int iter[MaxCount];

void AddEdge(int from, int to, int cap)
{
	G[from].push_back(Edge(to, cap, G[to].size()));
	G[to].push_back(Edge(from, 0, G[from].size() - 1));
}

void Bfs(int s)
{
	std::memset(level, -1, sizeof(level));
	std::queue<int> que;
	level[s] = 0;
	que.push(s);
	while (!que.empty())
	{
		int v = que.front();
		que.pop();
		for (int i = 0;i < G[v].size();++i)
		{
			Edge& e = G[v][i];
			if (e.cap > 0 && level[e.to] < 0)
			{
				level[e.to] = level[v] + 1;
				que.push(e.to);
			}
		}
	}
}

int Dfs(int v, int t, int f)
{
	if (v == t) return f;
	for (int& i = iter[v];i < G[v].size();++i)
	{
		Edge& e = G[v][i];
		if (e.cap > 0 && level[v] < level[e.to])
		{
			int d = Dfs(e.to, t, std::min(f, e.cap));
			if (d > 0)
			{
				e.cap -= d;
				G[e.to][e.rev].cap += d;
				return d;
			}
		}
	}
	return 0;
}

int MaxFlow(int s, int t)
{
	int flow = 0;
	for (;;)
	{
		Bfs(s);
		if (level[t] < 0) return flow;
		std::memset(iter, 0, sizeof(iter));
		int f;
		while ((f = Dfs(s,t,INT_MAX)) > 0)
		{
			flow += f;
		}
	}
}
int P;
int input[MaxCount][12];
int output[MaxCount][12];
int capacity[MaxCount];
std::vector<std::pair<int, int> > outBuffer;

bool IsConnected(int s, int t)
{
	for (int i = 0;i < P;++i)
	{
		if (output[s][i] + input[t][i] == 1)
			return false;
	}
	return true;
}


bool IsEnd(int s)
{
	for (int i = 0;i < P;++i)
	{
		if (output[s][i]!= 1)
			return false;
	}
	return true;
}

int main()
{
	std::ios::ios_base::sync_with_stdio(false);
	int N;
	while (std::cin >> P >> N)
	{
		for (int i = 0;i < N;++i)
		{
			std::cin >> capacity[i];
			for (int j = 0; j < P;++j)
			{
				std::cin >> input[i][j];
			}
			for (int j = 0; j < P;++j)
			{
				std::cin >> output[i][j];
			}
		}
		for (int i = 0; i < P;++i)
		{
			input[2 * N + 1][i] = 1;
			output[2 * N][i] = 0;
		}
		for (int i = 0;i < N;++i)
		{
			AddEdge(i, i + N, capacity[i]);
			if (IsConnected(2*N,i))
			{
				AddEdge(2 * N, i, INT_MAX);
			}
			if (IsEnd(i))
			{
				AddEdge(i + N, 2 * N + 1, INT_MAX);
			}	
			for (int j = 0;j < N;++j)
			{
				if (IsConnected(i, j))
				{
					AddEdge(i+N, j, capacity[i]);
				}
			}
		}
		std::cout << MaxFlow(2 * N, 2 * N + 1) << " ";
		for (int i = N;i < 2*N;++i)
		{
			for (int j = 0;j < G[i].size();++j)
			{
				Edge& e = G[i][j];
				if (e.to != 2*N+1 && e.cap != capacity[i-N]&&i-N!=e.to)
				{
					outBuffer.push_back(std::make_pair(i, j));
				}
			}
		}
		std::cout << outBuffer.size() << "\n";
		for (int i = 0;i < outBuffer.size();++i)
		{
			std::pair<int, int>& p = outBuffer[i];
			Edge& e = G[p.first][p.second];
			std::cout << p.first - N + 1 << " " <<
				e.to + 1 << " " << capacity[p.first - N] - e.cap << "\n";
		}
		for (int i = 0;i <= 2*N+1;++i)
		{
			G[i].clear();
		}
		outBuffer.clear();
	}
	return 0;
}