[蓝书/Ch5] The K-League UVALive

来源：互联网发布：数控车g76编程实例编辑：程序博客网时间：2024/05/16 06:57
题目链接
首先算出i在剩下比赛中全部获胜,看剩下的是否互相牵制,这样就转化成了公平分配问题的模型.

#include<bits/stdc++.h>using namespace std;typedef long long ll;const int maxn = 1000 + 10;const int INF = 1000000000;struct Edge {  int from, to, cap, flow;};bool operator < (const Edge& a, const Edge& b) {  return a.from < b.from || (a.from == b.from && a.to < b.to);}struct Dinic {  int n, m, s, t;  vector<Edge> edges;    // 边数的两倍  vector<int> G[maxn];   // 邻接表，G[i][j]表示结点i的第j条边在e数组中的序号  bool vis[maxn];         // BFS使用  int d[maxn];           // 从起点到i的距离  int cur[maxn];        // 当前弧指针  void ClearAll(int n) {    for(int i = 0; i < n; i++) G[i].clear();    edges.clear();  }  void ClearFlow() {    for(int i = 0; i < edges.size(); i++) edges[i].flow = 0;  }  void AddEdge(int from, int to, int cap) {    edges.push_back((Edge){from, to, cap, 0});    edges.push_back((Edge){to, from, 0, 0});    m = edges.size();    G[from].push_back(m-2);    G[to].push_back(m-1);  }  bool BFS() {    memset(vis, 0, sizeof(vis));    queue<int> Q;    Q.push(s);    vis[s] = 1;    d[s] = 0;    while(!Q.empty()) {      int x = Q.front(); Q.pop();      for(int i = 0; i < G[x].size(); i++) {        Edge& e = edges[G[x][i]];        if(!vis[e.to] && e.cap > e.flow) {          vis[e.to] = 1;          d[e.to] = d[x] + 1;          Q.push(e.to);        }      }    }    return vis[t];  }  int DFS(int x, int a) {    if(x == t || a == 0) return a;    int flow = 0, f;    for(int& i = cur[x]; i < G[x].size(); i++) {      Edge& e = edges[G[x][i]];      if(d[x] + 1 == d[e.to] && (f = DFS(e.to, min(a, e.cap-e.flow))) > 0) {        e.flow += f;        edges[G[x][i]^1].flow -= f;        flow += f;        a -= f;        if(a == 0) 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;  }  vector<int> Mincut() { // call this after maxflow    vector<int> ans;    for(int i = 0; i < edges.size(); i++) {      Edge& e = edges[i];      if(vis[e.from] && !vis[e.to] && e.cap > 0) ans.push_back(i);    }    return ans;  }  void Reduce() {    for(int i = 0; i < edges.size(); i++) edges[i].cap -= edges[i].flow;  }};Dinic g;int n;int T;int w[100];int d[100];int a[100][100];inline int getnum(int x,int y){    return n+(x-1)*n+y;}vector<int> ans;int main(){//    freopen("data.txt","r",stdin);    ios_base::sync_with_stdio(false);    cin >> T;    while(T--)    {        ans.clear();        cin >> n;        for(int i=1;i<=n;i++)        {            cin >> w[i]>>d[i];        }        for(int i=1;i<=n;i++)        {            for(int j=1;j<=n;j++)            {                cin >> a[i][j];            }        }        int s = 0;        int t = n*n+n+1;        for(int i=1;i<=n;i++)        {            int total = w[i];            for(int j=1;j<=n;j++)            {                total += a[i][j];            }            g.ClearAll(t+5);            int sum = 0;            for(int j=1;j<=n;j++)            {                for(int jj=1;jj<j;jj++)                {                    if(j==i||jj==i) continue;                    int num = getnum(j,jj);                    sum += a[j][jj];                    g.AddEdge(s,num,a[j][jj]);                    g.AddEdge(num,j,INF);                    g.AddEdge(num,jj,INF);                }            }//            cout <<total<<"&&"<<endl;            int f= 0;            for(int j=1;j<=n;j++)            {                if(w[j]>total)                {                    f = 1;                    break;                }                if(j==i) continue;                g.AddEdge(j,t,total-w[j]);            }            if(f)            {                continue;            }            if(g.Maxflow(s,t)==sum)            {                ans.push_back(i);            }        }        for(int i=0;i<ans.size();i++)        {            cout << ans[i];            if(i!=ans.size()-1)                cout <<" ";        }        cout << endl;    }    return 0;}
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