NOI2010 海拔

http://www.lydsy.com/JudgeOnline/problem.php?id=2007

平面图网络流。

好吧，其实我只会暴力的网络流，并不会平面图网络流。

Orz~

http://www.cnblogs.com/proverbs/archive/2012/08/28/2660307.html

http://blog.csdn.net/orpinex/article/details/7171640

#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<fstream>
#include<algorithm>
#include<cstring>
#include<string>
#include<cmath>
#include<queue>
#include<stack>
#include<map>
#include<utility>
#include<set>
#include<bitset>
#include<vector>
#include<functional>
#include<deque>
#include<cctype>
#include<climits>
#include<complex>
//#include<bits/stdc++.h>适用于CF,UOJ，但不适用于poj
 
using namespace std;

typedef long long LL;
typedef double DB;
typedef pair<int,int> PII;
typedef complex<DB> CP;

#define mmst(a,v) memset(a,v,sizeof(a))
#define mmcy(a,b) memcpy(a,b,sizeof(a))
#define fill(a,l,r,v) fill(a+l,a+r+1,v)
#define re(i,a,b)  for(i=a;i<=b;i++)
#define red(i,a,b) for(i=a;i>=b;i--)
#define ire(i,x) for(typedef(x.begin()) i=x.begin();i!=x.end();i++)
#define fi first
#define se second
#define m_p(a,b) make_pair(a,b)
#define SF scanf
#define PF printf
#define two(k) (1<<(k))

template<class T>inline T sqr(T x){return x*x;}
template<class T>inline void upmin(T &t,T tmp){if(t>tmp)t=tmp;}
template<class T>inline void upmax(T &t,T tmp){if(t<tmp)t=tmp;}

const DB EPS=1e-9;
inline int sgn(DB x){if(abs(x)<EPS)return 0;return(x>0)?1:-1;}
const DB Pi=acos(-1.0);

inline int gint()
  {
        int res=0;bool neg=0;char z;
        for(z=getchar();z!=EOF && z!='-' && !isdigit(z);z=getchar());
        if(z==EOF)return 0;
        if(z=='-'){neg=1;z=getchar();}
        for(;z!=EOF && isdigit(z);res=res*10+z-'0',z=getchar());
        return (neg)?-res:res; 
    }
inline LL gll()
  {
      LL res=0;bool neg=0;char z;
        for(z=getchar();z!=EOF && z!='-' && !isdigit(z);z=getchar());
        if(z==EOF)return 0;
        if(z=='-'){neg=1;z=getchar();}
        for(;z!=EOF && isdigit(z);res=res*10+z-'0',z=getchar());
        return (neg)?-res:res; 
    }

const int maxN=500;
const int INF=1<<30;

int N;
int mp[maxN+10][maxN+10][4];
int dis[maxN+10][maxN+10];
int ans;

struct V{int x,y;int v;inline V(int _x=0,int _y=0,int _v=0){x=_x;y=_y;v=_v;}};
struct cmp{inline bool operator ()(V a,V b){return a.v>b.v;}};
priority_queue<V,vector<V>,cmp>Q;

inline void Push(int x,int y,int v)
  {
      if(dis[x][y]>v){dis[x][y]=v;Q.push(V(x,y,v));}
      if(x==N)upmin(ans,v+mp[N+1][y][0]);
      if(y==1)upmin(ans,v+mp[x][1][1]);
  }

int main()
  {
      freopen("altitude.in","r",stdin);
      freopen("altitude.out","w",stdout);
      int i,j;
      N=gint();
      re(i,1,N+1)re(j,1,N)mp[i][j][0]=gint();
      re(i,1,N)re(j,1,N+1)mp[i][j][1]=gint();
      re(i,1,N+1)re(j,1,N)mp[i][j][2]=gint();
      re(i,1,N)re(j,1,N+1)mp[i][j][3]=gint();
      re(i,1,N)re(j,1,N)dis[i][j]=INF;
      ans=INF;
      re(i,1,N)Push(1,i,mp[1][i][0]);
      re(i,1,N)Push(i,N,mp[i][N+1][1]);
      while(!Q.empty())
        {
            int x=Q.top().x,y=Q.top().y,v=Q.top().v;
            Q.pop();
            if(v>dis[x][y])continue;
            if(x>1)Push(x-1,y,v+mp[x][y][2]);
            if(x<N)Push(x+1,y,v+mp[x+1][y][0]); 
            if(y>1)Push(x,y-1,v+mp[x][y][1]);
            if(y<N)Push(x,y+1,v+mp[x][y+1][3]);
        }
      cout<<ans<<endl;
      return 0;
  }