• luogu P4012 深海机器人问题


    费用流问题,每个样本选一次,就连一条capacity为1,权为给定的值,因为可以重复走,再连capacity为无穷,权为0的边,再一次连接给定的出点和汇点即可

    #include<bits/stdc++.h>
    using namespace std;
    #define lowbit(x) ((x)&(-x))
    typedef long long LL;
    
    const int maxm = 3e3+5;
    const int INF = 0x3f3f3f3f;
    
    struct edge{
        int u, v, cap, flow, cost, nex;
    } edges[maxm];
    
    int head[maxm], cur[maxm], cnt, fa[1024], d[1024], p, q;
    bool inq[1024];
    
    void init() {
        memset(head, -1, sizeof(head));
    }
    
    void add(int u, int v, int cap, int cost) {
        edges[cnt] = edge{u, v, cap, 0, cost, head[u]};
        head[u] = cnt++;
    }
    
    void addedge(int u, int v, int cap, int cost) {
        add(u, v, cap, cost), add(v, u, 0, -cost);
    }
    
    bool spfa(int s, int t, int &flow, LL &cost) {
        for(int i = 0; i <= p*q+3; ++i) d[i] = INF; //init()
        memset(inq, false, sizeof(inq));
        d[s] = 0, inq[s] = true;
        fa[s] = -1, cur[s] = INF;
        queue<int> q;
        q.push(s);
        while(!q.empty()) {
            int u = q.front();
            q.pop();
            inq[u] = false;
            for(int i = head[u]; i != -1; i = edges[i].nex) {
                edge& now = edges[i];
                int v = now.v;
                if(now.cap > now.flow && d[v] > d[u] + now.cost) {
                    d[v] = d[u] + now.cost;
                    fa[v] = i;
                    cur[v] = min(cur[u], now.cap - now.flow);
                    if(!inq[v]) {q.push(v); inq[v] = true;}
                }
            }
        }
        if(d[t] == INF) return false;
        flow += cur[t];
        cost += 1LL*d[t]*cur[t];
        for(int u = t; u != s; u = edges[fa[u]].u) {
            edges[fa[u]].flow += cur[t];
            edges[fa[u]^1].flow -= cur[t];
        }
        return true;
    }
    
    int MincostMaxflow(int s, int t, LL &cost) {
        cost = 0;
        int flow = 0;
        while(spfa(s, t, flow, cost));
        return flow;
    }
    
    void run_case() {
        init();
        int a, b, val;
        cin >> a >> b >> p >> q;
        p++, q++;
        for(int i = 1; i <= p; ++i)
            for(int j = 1; j < q; ++j) {
                cin >> val;
                addedge((i-1)*q+j, (i-1)*q+j+1, 1, -val);
                addedge((i-1)*q+j, (i-1)*q+j+1, INF, 0);
            }
        for(int i = 1; i <= q; ++i)
            for(int j = 1; j < p; ++j) {
                cin >> val;
                addedge((j-1)*q+i, j*q+i, 1, -val);
                addedge((j-1)*q+i, j*q+i, INF, 0);
            }
        int s = 0, t = p*q+2;
        for(int i = 0; i < a; ++i) {
            int k, x, y;
            cin >> k >> x >> y;
            x++, y++;
            addedge(s, (x-1)*q+y, k, 0);
        }
        for(int i = 0; i < b; ++i) {
            int k, x, y;
            cin >> k >> x >> y;
            x++, y++;
            addedge((x-1)*q+y, t, k, 0);
        }
        LL cost = 0;
        MincostMaxflow(s, t, cost);
        cout << -cost;
    }
    
    int main() {
        ios::sync_with_stdio(false), cin.tie(0);
        run_case();
        cout.flush();
        return 0;
    }
    View Code
  • 相关阅读:
    把IDEA中新建的项目提交到Github仓库中
    在IDEA中设置方法自动注释(带参数和返回值)
    如何在 Maven 工程中引入其他jar包 并生效?(以 Netty 为例)
    在 IDEA 中 配置 Maven
    Visio中锁定元件
    DevExpress中 TreeList控件的常规配置
    从SuperSocket的App.config中读取配置,并修改保存,再重启服务
    devexpress 中 XtraTabcontrol 改变BackColor 的方法
    DevExpress 中 GridControl 的数据源DataTable 内容改变后 重新绑定
    如何在linux中设置tab键长度
  • 原文地址:https://www.cnblogs.com/GRedComeT/p/12299123.html
Copyright © 2020-2023  润新知