QOJ.ac

QOJ

ID题目提交者结果用时内存语言文件大小提交时间测评时间
#318050#7185. Poor StudentsMinhhoTL 0ms0kbC++172.6kb2024-01-30 12:13:032024-01-30 12:13:03

Judging History

你现在查看的是最新测评结果

  • [2024-01-30 12:13:03]
  • 评测
  • 测评结果:TL
  • 用时:0ms
  • 内存:0kb
  • [2024-01-30 12:13:03]
  • 提交

answer

#define taskname "MCMF"
#include <bits/stdc++.h>
#define int long long
#define ii pair<int,int>
#define ff first
#define ss second

using namespace std;

const int maxn = 100005;
vector<int> adj[maxn];
int d[maxn], cur[maxn], cost, n, m, k, s, t, cnt;
struct edge {
    int u, v, f, c, w;
} e[maxn*100];
 mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

inline void add(int u, int v, int c, int w)
{
    // cout<<"ADD: "<<u<<" "<<v<<" "<<c<<" "<<w<<"\n";
    adj[u].emplace_back(cnt);
    e[cnt++] = {u, v, 0, c, w};
    adj[v].emplace_back(cnt);
    e[cnt++] = {v, u, 0, 0, -w};
}

inline bool BFS()
{
    fill(d+s, d+t+1, 1e18);
    d[s] = 0;
    priority_queue<ii, vector<ii>, greater<ii>> pq;
    pq.emplace(0, s);
    while (pq.size())
    {
        auto [du, u] = pq.top(); pq.pop();
        for (int id: adj[u])
        {
            auto [_, v, f, c, w] = e[id];
            if (f < c && cost >= w && d[v] > d[u] + w)
            {
                d[v] = d[u] + w;
                pq.emplace(d[v], v);
            }
        }
    }
    return (d[t] != 1e18);
}


int DFS(int u, int flow)
{
    if (u == t) return flow;
    for (int &i=cur[u]; i<adj[u].size();)
    {
        int id = adj[u][i++];
        auto [_, v, f, c, w] = e[id];
        if (f < c && d[v] == d[u] + w)
        {
            int x = DFS(v, min(flow, c - f));
            if (x)
            {
                e[id].f += x;
                e[id^1].f -= x;
                return x;
            }
        }
    }
    return 0;
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    if (fopen("input.in", "r")) {
        freopen("input.in", "r", stdin);
        freopen("output.out", "w", stdout);
    }
    cin>>n>>k;
    assert(n <= 1e4);
    s = 0, t = n + k + 1;
    for (int i=1, u, v, c, w; i<=n; i++)
    {
        add(0, i, 1, 0);
        u = i;
        vector<ii> ve;
        for (v=n+1; v<=n+k; v++)
        {
            cin>>w;
            ve.emplace_back(w, v);
        }
        shuffle(ve.begin(), ve.end(), rng);
        for (auto [w, v]: ve) add(u, v, 1, w);
    }
    for (int i=1; i<=k; i++)
    {
        int c; cin>>c;
        if (c) add(n+i, t, c, 0);
    }
    int ans = 0, need = n;
    for (cost=1; ; cost <<= 1)
    {
        while (BFS() && need)
        {
            fill(cur+s, cur+t+1, 0);
            int x;
            while (x = DFS(s, need))
            {
                ans += x * d[t];
                need -= x;
                if (!need) break;
            }
        }
    }
    cout<<ans;
}

详细

Test #1:

score: 0
Time Limit Exceeded

input:

6 2
1 2
1 3
1 4
1 5
1 6
1 7
3 4

output:


result: