hdu_1532_Drainage Ditches

#include<iostream>  #include<sstream>  #include<string>  #include<vector>  #include<list>  #include<set>  #include<map>#include<stack>  #include<queue>  #include<algorithm>  #include<numeric>  #include<cmath>#include<cstdio>#include<cstdlib>#include<cstring>#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 MaxVexNum = 1000;const int INF = 1000000000;class Edge{public:int to, capacity, flow;Edge(int t, int c, int f){to = t,capacity = c,flow = f;}};class Network{private:int vexnum, edgenum, source, destination,maxflow;vector<vector<Edge>>adjList;public:void addEdge(int from, int to, int cap){adjList[from].push_back({ to, cap, (int)adjList[to].size() });adjList[to].push_back({ from, 0, (int)adjList[from].size() - 1 });}Network(){adjList.resize(MaxVexNum);cin >> edgenum >> vexnum;source = 1, destination = vexnum;for (int i = 0; i < edgenum; i++){int from, to, capacity;cin >> from >> to >> capacity;addEdge(from, to, capacity);}}int dfs(int src, int sink, int flow,vector<bool>&used){if (src == sink){return flow;}used[src] = true;for (int i = 0; i<adjList[src].size(); i++){Edge &edge = adjList[src][i];if (!used[edge.to] && edge.capacity>0){int minflow = dfs(edge.to, sink, std::min(flow, edge.capacity),used);if (minflow>0){edge.capacity -= minflow;adjList[edge.to][edge.flow].capacity += minflow;return minflow;}}}return 0;}void getMaxFlow(){maxflow = 0;while (1){vector<bool>used(MaxVexNum);int f = dfs(source, destination, INF,used);if (!f){return;}maxflow += f;}}void print(){cout << maxflow << endl;}};int main(){//freopen("input.txt", "r", stdin);char ch;while ((ch = cin.get()) != EOF){ungetc(ch,stdin);Network network;network.getMaxFlow();network.print();cin.get();}return 0;}