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Shiroha白羽的博客

Golang 踩坑 —— interface 为参数的时候传 nil 指针 Codeforces Round 925 (Div. 3) Codeforces Round 924 (Div. 2) Codeforces Round 923 (Div. 3) Codeforces Round 922 (Div. 2) Codeforces Round 921 (Div. 2) Educational Codeforces Round 161 (Rated for Div. 2) Codeforces Round 920 (Div. 3) Codeforces Round 919 (Div. 2) Hello 2024 Good Bye 2023 Codeforces Round 918 (Div. 4) 个人备份的常用 macOS 清理命令 Codeforces Round 917 (Div. 2) Pinely Round 3 (Div. 1 + Div. 2) Educational Codeforces Round 160 (Rated for Div. 2) Codeforces Round 915 (Div. 2) Codeforces Round 914 (Div. 2) Codeforces Round 913 (Div. 3) Educational Codeforces Round 159 (Rated for Div. 2) Codeforces Round 912 (Div. 2) Codeforces Round 911 (Div. 2) CodeTON Round 7 (Div. 1 + Div. 2, Rated, Prizes!) Educational Codeforces Round 158 (Rated for Div. 2) Codeforces Round 910 (Div. 2) Codeforces Round 909 (Div. 3) Codeforces Round 908 (Div. 2) Educational Codeforces Round 157 (Rated for Div. 2) C++自定义的字面量 Codeforces Round 907 (Div. 2)
【2020HDU多校】第二场1005(HDU6767)New Equipments——费用流
Shiroha · 2020-07-24 · via Shiroha白羽的博客

给出 $n$ 个工人和 $m$ 件装备,装备的编号为 $1, 2, 3 … m$。
对于工人 $i$ ,他有三个参数 $a_i, b_i, c_i$,当为这个工人装备了第 $j$ 个装备时,需要花费 $a_i j ^ 2+ b_i j + c_i$ 的费用。
当为 $k$ 个工人装备上装备时,最小花费是多少。
对所有的 $k$ 的情况均需要输出

费用流
将每个员工与源点链接,取每个员工的二次函数曲线的最小值附近的 $n$ 个点,与员工相连,所有的在二次函数曲线上的点与汇点相连,员工连接到二次函数的线需要设定费用,其他线费用均为 $0$,所有线的流量均为 $1$

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#include <bits/stdc++.h>

using namespace std;

#define ll long long

const ll maxn = 3000;
const ll INF = 0x3f3f3f3f3f3f3f3f;

bool flag;

struct Edge {
ll from, to, cap, flow, cost;

Edge(ll u, ll v, ll c, ll f, ll cc)
: from(u), to(v), cap(c), flow(f), cost(cc) {}
};

struct MCMF {
ll n, m;
vector<Edge> edges;
vector<ll> G[maxn];
ll inq[maxn]; //是否在队列中
ll d[maxn]; //bellmanford
ll p[maxn]; //上一条弧
ll a[maxn]; //可改进量
void init(ll nn) {
this->n = nn;
for (ll i = 0; i <= n; ++i) G[i].clear();
edges.clear();
}

void addEdge(ll from, ll to, ll cap, ll cost) {
edges.emplace_back(Edge(from, to, cap, 0, cost));
edges.emplace_back(Edge(to, from, 0, 0, -cost));
m = (ll) (edges.size());
G[from].emplace_back(m - 2);
G[to].emplace_back(m - 1);
}

bool spfa(ll s, ll t, ll &flow, ll &cost) {
for (ll i = 1; i <= n; ++i) d[i] = INF;
memset(inq, 0, sizeof(inq));
d[s] = 0;
inq[s] = 1;
p[s] = 0;
queue<ll> q;
a[s] = INF;
q.push(s);
while (!q.empty()) {
ll u = q.front();
q.pop();
inq[u] = 0;
for (ll i = 0; i < (ll) (G[u].size()); ++i) {
Edge &e = edges[G[u][i]];
if (e.cap > e.flow && d[e.to] > d[u] + e.cost) {
d[e.to] = d[u] + e.cost;
p[e.to] = G[u][i];
a[e.to] = min(a[u], e.cap - e.flow);
if (!inq[e.to]) {
q.push(e.to);
inq[e.to] = 1;
}
}
}
}
if (d[t] == INF) return false;
flow += a[t];
cost += (ll) d[t] * (ll) a[t];
cout << (flag ? " " : "") << cost;
flag = true;
for (ll u = t; u != s; u = edges[p[u]].from) {
edges[p[u]].flow += a[t];
edges[p[u] ^ 1].flow -= a[t];
}
return true;
}

ll MincostMaxflow(ll s, ll t, ll &cost) {
ll flow = 0;
cost = 0;
while (spfa(s, t, flow, cost));
return flow;
}
} mcmf;

struct Node {
ll a, b, c;
ll l, r;

ll cal(ll x) {
return a * x * x + b * x + c;
}

void make(ll n, ll m) {
ll mid = -b / 2 / a;
l = mid - n / 2 - 1;
r = mid + n / 2 + 1;
l = max(1ll, l);
r = min(m, r);
if (r == m) {
l = r - n - 2;
} else if (l == 1) {
r = l + n + 2;
}
}
} node[60];

void solve() {
ll T;
cin >> T;
for (ll ts = 0; ts < T; ++ts) {
flag = false;
unordered_map<ll, ll> trans;
ll n, m;
cin >> n >> m;
ll ind = 51;
for (ll i = 1; i <= n; ++i) {
cin >> node[i].a >> node[i].b >> node[i].c;
node[i].make(n, m);
ll l = node[i].l;
ll r = node[i].r;
assert(r - l < 60);
for (ll j = l; j <= r; ++j) {
if (trans.count(j)) continue;
trans.insert({j, ind++});
}
}
ll source = ind + 10, target = ind + 11;
mcmf.init(target + 10);
#ifdef ACM_LOCAL
cerr << target + 10 << endl;
#endif
for (auto &item : trans)
mcmf.addEdge(item.second, target, 1, 0);
for (ll i = 1; i <= n; ++i) {
mcmf.addEdge(source, i, 1, 0);
for (ll j = node[i].l; j <= node[i].r; ++j) {
mcmf.addEdge(i, trans[j], 1, node[i].cal(j));
}
}
ll cost;
mcmf.MincostMaxflow(source, target, cost);
cout << endl;
}
}

signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
#ifdef ACM_LOCAL
freopen("in.txt", "r", stdin);
freopen("out.txt", "w", stdout);
signed test_index_for_debug = 1;
char acm_local_for_debug;
while (cin >> acm_local_for_debug) {
if (acm_local_for_debug == '$') exit(0);
cin.putback(acm_local_for_debug);
if (test_index_for_debug > 20) {
throw runtime_error("Check the stdin!!!");
}
auto start_clock_for_debug = clock();
solve();
auto end_clock_for_debug = clock();
cout << "Test " << test_index_for_debug << " successful" << endl;
cerr << "Test " << test_index_for_debug++ << " Run Time: "
<< double(end_clock_for_debug - start_clock_for_debug) / CLOCKS_PER_SEC << "s" << endl;
cout << "--------------------------------------------------" << endl;
}
#else
solve();
#endif
return 0;
}