uva_259_Software Allocation

<pre name="code" class="cpp">#include<iostream>  
#include<sstream>  
#include<string>  
#include<vector>  
#include<list>  
#include<set>  
#include<map>
#include<stack>  
#include<queue>  
#include<algorithm>  
#include<numeric>  
#include<cmath>  
#pragma warning(disable:4996)  
using std::cin;
using std::cout;
using std::endl;
using std::stringstream;
using std::string;
using std::vector;
using std::list;
using std::pair;
using std::set;
using std::multiset;
using std::map;
using std::multimap;
using std::stack;
using std::queue;
using std::priority_queue;
const int infinity =1000000000;
class Network
{
private:
	int vexnum, edgenum, maxflow, source, destination;
	vector<vector<int>>flow, capacity;
	map<int, char>number_task;//任务的编号和名称  
	vector<int>index;
public:
	void addEdge()
	{
		int from, to, c; cin >> from >> to >> c;
		capacity[from - 1][to - 1] += c;
	}
	void addEdge(const int &from,const int &to,const int &c)
	{
		capacity[from][to] = c;
	}
	Network()
	{
		maxflow = destination = 0; source = 10;
		flow.resize(100, (vector<int>)100), capacity.resize(100, (vector<int>)100);
		index.resize(10);
		//连接pc到汇点  
		for (int i = 1; i <= 10; i++)
		{
			addEdge(i, destination, 1); 
		}
		//连接任务到pc  
		string str;
		while (getline(cin, str) && !str.empty())
		{
			stringstream stream; stream << str;
			char task; int number; stream >> task >> number;
			//flow.resize(flow.size()+number, (vector<int>)(flow.size() + number)), capacity.resize(capacity.size() + number, (vector<int>)(capacity.size() + number));
			for (int i = 1; i <= number; i++)
			{
				number_task.insert({ source + i,task });//记录顶点号和任务的一一对应关系  
			}
			char computer;
			while (stream >> computer)
			{
				if (computer == ';')
				{
					break;
				}
				int pc = computer - '0' + 1;
				for (int i = 1; i <= number; i++)
				{
					addEdge(source + i, pc, 1); 
				}
			}
			source += number;
		}
		source++;
		//flow.resize(flow.size() + 1, (vector<int>)(flow.size() + 1)), capacity.resize(capacity.size() + 1, (vector<int>)(capacity.size() + 1));
		//建立源点到任务的联系  
		for (int i = 11; i<source; i++)
		{
			addEdge(source, i, 1);
		}
		vexnum = source + 1;
	}
	void getMaxFlow_EK() 
	{
		maxflow = 0;
		queue<int> Q;
		while (!Q.empty())
		{
			Q.pop();
		}
		vector<int>path(vexnum);
		while (true) 
		{
			vector<int>remnant(vexnum);//残余流量得变0,一开始所有点都没流入对吧
			remnant[source] = infinity;   //源点嘛,剩余流量无限是必须的...
			Q.push(source);    //从源点开始进行BFS找增广路
			int from, to;
			while (!Q.empty())
			{
				from = Q.front();Q.pop();
				for (to = 0; to < vexnum; to++)//遍历所有点,找可行边
				{
					if (!remnant[to] && capacity[from][to]>flow[from][to])
					{    //该点剩余流量为0 且 容量大于流量,也就是找到了新的结点 
						path[to] = from;   //找到新结点,父节点得记录一下吧
						Q.push(to);
						remnant[to] = std::min(remnant[from], capacity[from][to] - flow[from][to]);    //如果u的剩余流量能填满uv就填满,不能的话就把u这点的流量全部流向uv 
					}
				}
			}
			if (remnant[destination] == 0)     //如果当前已经是最大流,汇点没有残余流量
			{
				break;
			}
			for (from = destination; from != source; from = path[from]) 
			{   //如果还能增广,那么回溯,从汇点往回更新每条走过的边的流量
				if (from >= 1 && from <= 10)
				{
					index[from - 1] = path[from];
				}
				flow[path[from]][from] += remnant[destination];  //更新正向流量   （注意这里更新的是流量，而不是容量）
				flow[from][path[from]] -= remnant[destination];  //更新反向流量
			}
			maxflow += remnant[destination];
		}
	}
	void print()
	{
		if (maxflow != number_task.size())
		{
			cout << '!' << endl;
		}
		else
		{
			for (int i = 0; i < 10; i++)
			{
				if (index[i])
				{
					cout << number_task[index[i]];
				}
				else
				{
					cout << '_';
				}
			}
			cout << endl;
		}
	}
};
int main()
{
	//freopen("input.txt", "r", stdin);  
	//freopen("output.txt", "w", stdout);  
	char ch;
	while ((ch = cin.get()) != EOF)
	{
		ungetc(ch, stdin);
		Network network;
		network.getMaxFlow_EK();
		network.print();
	}
	return 0;
}