记录编号 |
277575 |
评测结果 |
AAAAAAAAAA |
题目名称 |
[网络流24题] 运输问题 |
最终得分 |
100 |
用户昵称 |
prefect1999 |
是否通过 |
通过 |
代码语言 |
C++ |
运行时间 |
0.018 s |
提交时间 |
2016-07-05 22:52:31 |
内存使用 |
0.33 MiB |
显示代码纯文本
/*
费用流:
源点向仓库连边,容量为a[i]。
仓库向零售店连边,容量为inf,费用为c[i][j](最优方案),费用为-c[i][j](最差方案)。
零售店向汇点连边,容量为b[i]。
*/
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;
const int inf = 1 << 30;
const int maxn = 500;
struct edge
{
int from, to, cap, flow, cost;
edge(int u, int v, int c, int f, int w) : from(u), to(v), cap(c), flow(f), cost(w){}
};
struct MCMF
{
int n, m;
vector<edge> edges;
vector<int> G[maxn];
int inq[maxn];
int d[maxn];
int p[maxn];
int a[maxn];
void init(int n)
{
this->n = n;
for (int i = 0; i < n; ++i)
G[i].clear();
edges.clear();
}
void add_edge(int from, int to, int cap, int cost)
{
edges.push_back(edge(from, to, cap, 0, cost));
edges.push_back(edge(to, from, 0, 0, -cost));
m = edges.size();
G[from].push_back(m - 2);
G[to].push_back(m - 1);
}
bool BellmanFord(int s, int t, int &flow, long long &cost)
{
for (int i = 0; i < n; ++i)
d[i] = inf;
memset(inq, 0, sizeof(inq));
d[s] = 0; inq[s] = 1; p[s] = 0; a[s] = inf;
queue<int> Q;
Q.push(s);
while (!Q.empty())
{
int u = Q.front(); Q.pop();
inq[u] = false;
for (int i = 0; i < (int)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] = true;
}
}
}
}
if (d[t] == inf)
return false;
flow += a[t];
cost += (long long)d[t] * (long long)a[t];
for (int u = t; u != s; u = edges[p[u]].from)
{
edges[p[u]].flow += a[t];
edges[p[u]^1].flow -= a[t];
}
return true;
}
int solve(int s, int t, long long &cost)
{
int flow = 0; cost = 0;
while (BellmanFord(s, t, flow, cost));
return flow;
}
}mcmf;
int A[maxn], B[maxn];
int main()
{
freopen("tran.in", "r", stdin);
freopen("tran.out", "w", stdout);
int n, m;
scanf("%d %d", &m, &n);
long long cost = 0;
const int s = n + m + 2, t = n + m + 3;
mcmf.init(n + m + 5);
for (int i = 0; i < m; ++i)
{
scanf("%d", &A[i]);
mcmf.add_edge(s, i, A[i], 0);
}
for (int i = 0; i < n; ++i)
{
scanf("%d", &B[i]);
mcmf.add_edge(m + i, t, B[i], 0);
}
for (int i = 0; i < m; ++i)
{
for (int j = 0; j < n; ++j)
{
int cost;
scanf("%d", &cost);
mcmf.add_edge(i, m + j, inf, cost);
}
}
mcmf.solve(s, t, cost);
cout << cost << endl;
for (int i = 0; i < (int)mcmf.edges.size(); ++i)
{
edge &e = mcmf.edges[i];
e.flow = 0;
e.cost = -e.cost;
}
mcmf.solve(s, t, cost);
cout << -cost << endl;
return 0;
}