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zc
2020-01-18 21:03:00
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[国家集训队]happiness有点像

而且建图更加简化了

答案为总和减去最小割

(i+j)\&1,(i',j')(i,j)相邻,黑白染色建图

st\xrightarrow{A} (i,j)\xrightarrow{B}ed

st\xrightarrow{B} (i',j')\xrightarrow{A}ed

(i,j) \xleftrightarrow{c_{i,j}+c_{i',j'}} (i',j')

ABBAc[i][j]+c[i'][j']c[i][j]+c[i'][j']sti,ji',j'ed

假设(i,j)选择A,那么要断开(i,j)\rightarrow t,(i,j)\rightarrow (i',j')

这些边上的权值会从答案中减去

最小割可以最小化要减去的权值,所以答案最大

#include<bits/stdc++.h>
namespace ZDY{
    #pragma GCC optimize(3)
    #define il __inline__ __attribute__ ((always_inline))
    #define register
    #define ll long long
    #define ull unsigned long long
    #define db double
    #define sht short
    #define MB template <class T>il
    #define Fur(i,x,y) for(int i(x);i<=y;++i)
    #define Fdr(i,x,y) for(int i(x);i>=y;--i)
    #define fl(i,x) for(int i(head[x]),to;to=e[i].to,i;i=e[i].nxt)
    #define clr(x,y) memset(x,y,sizeof(x))
    #define cpy(x,y) memcpy(x,y,sizeof(x))
    #define fin(s) freopen(s".in","r",stdin)
    #define fout(s) freopen(s".out","w",stdout)
    #define fcin ios::sync_with_stdio(false)
    #define l2(n) ((int)(log2(n)))
    #define inf 2122219134
    MB T ABS(T x){return x>0?x:-x;}
    MB T MAX(T x,T y){return x>y?x:y;}
    MB T MIN(T x,T y){return x<y?x:y;}
    MB T GCD(T x,T y){return y?GCD(y,x%y):x;}
    MB void SWAP(T &x,T &y){T t=x;x=y;y=t;}
}using namespace ZDY;using namespace std;
namespace IO{const int str=1<<20;static char in_buf[str],*in_s,*in_t;bool __=0;il char gc(){return (in_s==in_t)&&(in_t=(in_s=in_buf)+fread(in_buf,1,str,stdin)),in_s==in_t?__=1,EOF:*in_s++;}il void in(string &ch){ch.clear();if(__)return;char c;while((c=gc())!=EOF&&isspace(c));if(c==EOF){__=1;return;}ch+=c;while((c=gc())!=EOF&&!isspace(c))ch+=c;if(c==EOF)__=1;}il void in(char &ch){if(__)return;char c;while((c=gc())!=EOF&&isspace(c));if(c==EOF)__=1;else ch=c;}il void in(char *ch){*ch='\0';if(__)return;char c;while((c=gc())!=EOF&&isspace(c));if(c==EOF){__=1;return;}*ch=c;ch++;while((c=gc())!=EOF&&!isspace(c))*ch=c,ch++;if(c==EOF)__=1;*ch='\0';}template<typename T>il void in(T &x){if(__)return;char c=gc();bool f=0;while(c!=EOF&&(c<'0'||c>'9'))f^=(c=='-'),c=gc();if(c==EOF){__=1;return;}x=0;while(c!=EOF&&'0'<=c&&c<='9')x=x*10+c-48,c=gc();if(c==EOF)__=1;if(f)x=-x;}template<typename T,typename ... arr>il void in(T &x,arr & ... y){in(x),in(y...);}const char ln='\n';static char out_buf[str],*out_s=out_buf,*out_t=out_buf+str;il void flush(){fwrite(out_buf,1,out_s-out_buf,stdout);out_s=out_buf;}il void pt(char c){(out_s==out_t)?(fwrite(out_s=out_buf,1,str,stdout),*out_s++=c):(*out_s++=c);}il void out(const char* s){while(*s)pt(*s++);}il void out(char* s){while(*s)pt(*s++);}il void out(char c){pt(c);}il void out(string s){for(int i=0;s[i];i++)pt(s[i]);}template<typename T>il void out(T x){if(!x){pt('0');return;}if(x<0)pt('-'),x=-x;char a[50],t=0;while(x)a[t++]=x%10,x/= 10;while(t--)pt(a[t]+'0');}template<typename T,typename ... arr>il void out(T x,arr & ... y){out(x),out(y...);}}using namespace IO;
const int N=100011,M=1000011;
int n,m,cnt=1,head[N],st,ed,d[N],q[N],c[101][101];
struct edge{
    int to,nxt,w;
}e[M];
il void add(int x,int y,int w){
    e[++cnt].to=y;e[cnt].nxt=head[x];head[x]=cnt;e[cnt].w=w;
    e[++cnt].to=x;e[cnt].nxt=head[y];head[y]=cnt;e[cnt].w=0;
}
bool bfs(){
    int h=0,t=1,x;
    clr(d,0);
    q[0]=st;d[st]=1;
    while(h<t){
        x=q[h++];if(x==ed)return 1;
        fl(i,x)if(e[i].w&&!d[to])
            d[to]=d[x]+1,q[t++]=to;
    }
    return 0;
}
int dfs(int x,int mf){
    if(x==ed)return mf;
    int us=0,w;
    fl(i,x)if(e[i].w&&d[to]==d[x]+1){
        w=dfs(to,MIN(mf-us,e[i].w));
        e[i].w-=w;
        us+=w;
        e[i^1].w+=w;
        if(us==mf)return mf;
    }
    if(!us)d[x]=-1;
    return us;
}
int id(int x,int y){
    return (x-1)*m+y;
}
int main(){
    in(n,m);
    st=N-1,ed=N-2;
    int ans=0,w,tt=n*m,dx[4]={0,1,0,-1},dy[4]={1,0,-1,0},x,y;
    Fur(i,1,n)Fur(j,1,m){
        in(w),ans+=w;
        if((i+j)&1)add(st,id(i,j),w);
        else add(id(i,j),ed,w);
    }
    Fur(i,1,n)Fur(j,1,m){
        in(w),ans+=w;
        if((i+j)&1)add(id(i,j),ed,w);
        else add(st,id(i,j),w);
    }
    Fur(i,1,n)Fur(j,1,m)in(c[i][j]);
    Fur(i,1,n)Fur(j,1,m)
    if(!((i+j)&1))
    Fur(t,0,3){
        x=i+dx[t],y=j+dy[t];
        if(x<1||x>n||y<1||y>m)continue;
        ans+=(w=c[i][j]+c[x][y]);
        add(id(i,j),id(x,y),w);
        add(id(x,y),id(i,j),w);
    }
    while(bfs())ans-=dfs(st,inf);
    printf("%d\n",ans);
}
LG 1935 [国家集训队]圈地计划
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