Hdu-3572-Task

There are N jobs and M machines. Each job can only run on the same machine for one day, and only one job can be run on each machine for one day, the I-th job must be completed on the pi Day, and only Pi days can be selected from Si to Ei. If all the jobs can be completed (T <= 20, N <= 500, M <= 200, 1 <= Pi, Si, Ei <= 500 ). --> The original idea of creating a graph is as follows: Set a super source s, each job is a node, and one edge is connected to each job from s, the capacity is the time required to complete the job. When the full stream is sent from s, it is the number of days required for the job. Finally, check whether the maximum stream is full; the day that a job can select is also used as one node, and each job connects one edge to its selected day with a capacity of 1 (because each job can only run on the same machine one day, each machine can run only one job every day). Finally, all the days that can be selected are respectively directed to the super exchange t to connect one edge, the capacity is M (because only M machines are allowed per day )~ OK ~

#include <cstdio>  #include <vector>  #include <queue>  #include <algorithm>  #include <cstring>    using namespace std;    const int maxn = 1000 + 10;  const int INF = 0x3f3f3f3f;    int N, M;  bool flag[maxn];    struct Edge{      int u, v, cap, flow;      Edge(int u = 0, int v = 0, int cap = 0, int flow = 0):      u(u), v(v), cap(cap), flow(flow){}  };    struct Dinic{      vector<Edge> edges;      vector<int> G[maxn];      int m, s, t;      int d[maxn], cur[maxn];      bool vis[maxn];        void addEdge(int u, int v, int cap){          edges.push_back(Edge(u, v, cap, 0));          edges.push_back(Edge(v, u, 0, 0));          m = edges.size();          G[u].push_back(m-2);          G[v].push_back(m-1);      }        bool bfs(){          d[s] = 0;          memset(vis, 0, sizeof(vis));          queue<int> qu;          qu.push(s);          vis[s] = 1;          while(!qu.empty()){              int u = qu.front(); qu.pop();              int sz = G[u].size();              for(int i = 0; i < sz; i++){                  Edge& e = edges[G[u][i]];                  if(!vis[e.v] && e.cap > e.flow){                      d[e.v] = d[u] + 1;                      vis[e.v] = 1;                      qu.push(e.v);                  }              }          }          return vis[t];      }        int dfs(int u, int a){          if(u == t || a == 0) return a;          int f, flow = 0;          int sz = G[u].size();          for(int i = cur[u]; i < sz; i++){              Edge& e = edges[G[u][i]];              cur[u] = i;              if(d[e.v] == d[u] + 1 && (f = dfs(e.v, min(a, e.cap-e.flow))) > 0){                  e.flow += f;                  edges[G[u][i]^1].flow -= f;                  flow += f;                  a -= f;                  if(!a) break;              }          }          return flow;      }        int Maxflow(int s, int t){          this->s = s;          this->t = t;          int flow = 0;          while(bfs()){              memset(cur, 0, sizeof(cur));              flow += dfs(s, INF);          }          return flow;      }    };    int main()  {      int T, P, S, E, kase = 1;      scanf("%d", &T);      while(T--){          Dinic din;          scanf("%d%d", &N, &M);          memset(flag, 0, sizeof(flag));          int sum = 0;          for(int i = 1; i <= N; i++){              scanf("%d%d%d", &P, &S, &E);              din.addEdge(0, i, P);              for(int j = S; j <= E; j++){                  din.addEdge(i, N+j, 1);                  if(!flag[N+j]){                      din.addEdge(N+j, 1001, M);                      flag[N+j] = 1;                  }              }              sum += P;          }          if(din.Maxflow(0, 1001) == sum) printf("Case %d: Yes\n\n", kase++);          else printf("Case %d: No\n\n", kase++);      }      return 0;  }  

 

It is found that the above data structure is not as written as the following array:

#include <cstdio>  #include <queue>  #include <algorithm>  #include <cstring>    using namespace std;    const int maxn = 1000 + 10;  const int maxm = 502000 + 10;  const int INF = 0x3f3f3f3f;    int head[maxn], nxt[maxm], ecnt, v[maxm], flow[maxm], cap[maxm];  bool flag[maxn];  int N, M;    struct Dinic{      int m, s, t;      int d[maxn], cur[maxn];      bool vis[maxn];        Dinic(){          memset(head, -1, sizeof(head));          ecnt = 0;      }        void addEdge(int uu, int vv, int ca){          v[ecnt] = vv; cap[ecnt] = ca; flow[ecnt] = 0; nxt[ecnt] = head[uu]; head[uu] = ecnt; ecnt++;          v[ecnt] = uu; cap[ecnt] = 0; flow[ecnt] = 0; nxt[ecnt] = head[vv]; head[vv] = ecnt; ecnt++;      }        bool bfs(){          d[s] = 0;          memset(vis, 0, sizeof(vis));          queue<int> qu;          qu.push(s);          vis[s] = 1;          while(!qu.empty()){              int u = qu.front(); qu.pop();              for(int e = head[u]; e != -1; e = nxt[e]){                  if(!vis[v[e]] && cap[e] > flow[e]){                      d[v[e]] = d[u] + 1;                      vis[v[e]] = 1;                      qu.push(v[e]);                  }              }          }          return vis[t];      }        int dfs(int u, int a){          if(u == t || a == 0) return a;          int f, Flow = 0;          for(int e = cur[u]; e != -1; e = nxt[e]){              cur[u] = e;              if(d[v[e]] == d[u] + 1 && (f = dfs(v[e], min(a, cap[e]-flow[e]))) > 0){                  flow[e] += f;                  flow[e^1] -= f;                  Flow += f;                  a -= f;                  if(!a) break;              }          }          return Flow;      }        int Maxflow(int s, int t){          this->s = s;          this->t = t;          int Flow = 0;          while(bfs()){              memcpy(cur, head, sizeof(head));              Flow += dfs(s, INF);          }          return Flow;      }    };    int main()  {      int T, P, S, E, kase = 1;      scanf("%d", &T);      while(T--){          Dinic din;          scanf("%d%d", &N, &M);          memset(flag, 0, sizeof(flag));          int sum = 0;          for(int i = 1; i <= N; i++){              scanf("%d%d%d", &P, &S, &E);              din.addEdge(0, i, P);              for(int j = S; j <= E; j++){                  din.addEdge(i, N+j, 1);                  if(!flag[N+j]){                      din.addEdge(N+j, 1001, M);                      flag[N+j] = 1;                  }              }              sum += P;          }          if(din.Maxflow(0, 1001) == sum) printf("Case %d: Yes\n\n", kase++);          else printf("Case %d: No\n\n", kase++);      }      return 0;  }