POJ 3686 The Windy's (最小费用流或最佳完全匹配)

2021-05-07 00:30

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题意:有n个订单m个车间,每个车间均可以单独完成任何一个订单。每个车间完成不同订单的时间是不同的。不会出现两个车间完成同一个订单的情况。给出每个订单在某个车间完成所用的时间。问订单完成的平均时间是多少。

析:这个题可以用最小费用流或者最佳完全匹配来做,因为只有车间和订单,满足二分图,主要是在建图。

代码如下:

#pragma comment(linker, "/STACK:1024000000,1024000000")
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#define debug() puts("++++");
#define gcd(a, b) __gcd(a, b)
#define lson l,m,rt P;
const int INF = 0x3f3f3f3f;
const double inf = 1e20;
const double PI = acos(-1.0);
const double eps = 1e-8;
const int maxn = 50 * 50 + 100 + 10;
const int maxm = 1e5 + 10;
const int mod = 50007;
const int dr[] = {-1, 0, 1, 0};
const int dc[] = {0, -1, 0, 1};
const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};
int n, m;
const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
inline bool is_in(int r, int c) {
  return r >= 0 && r = 0 && c  edges;
  vector G[maxn];
  bool inq[maxn];
  int d[maxn];
  int p[maxn];
  int a[maxn];

  void init(int n){
    this-> n = n;
    for(int i = 0; i  q;
    q.push(s);

    while(!q.empty()){
      int u = q.front();  q.pop();
      inq[u] = 0;
      for(int i = 0; i  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;
    cost += a[t] * d[t];
    flow += a[t];
    int u = t;
    while(u != s){
      edges[p[u]].flow += a[t];
      edges[p[u]^1].flow -= a[t];
      u = edges[p[u]].from;
    }
    return true;
  }

  int mincostmaxflow(int s, int t){
    this->s = s;  this->t = t;
    int flow = 0, cost = 0;
    while(bellman(flow, cost));
    return cost;
  }
};
MinCostMaxFlow mcmf;

int a[55][55];

int main(){
  int T;  cin >> T;
  while(T--){
    scanf("%d %d", &n, &m);
    int s = 0, t = n * m + n + 2;
    mcmf.init(t + 10);
    for(int i = 1; i 

  

POJ 3686 The Windy's (最小费用流或最佳完全匹配)

标签:pop   front   unsigned   +++   debug   ace   memset   init   inf   

原文地址:http://www.cnblogs.com/dwtfukgv/p/7652116.html


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