我再也不相信正解了……
Posted coder-cjh
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RT，正解居然是暴搜，我用的是Hamilton，结果炸了
Code
Mine
#include<bits/stdc++.h> #pragma GCC optimize("O2") #define fr(i,a,b) for(int i=a;i<=b;++i) #define rf(i,a,b) for(int i=a;i>=b;--i) #define min(a,b) (a<b?a:b) #define max(a,b) (a>b?a:b) #define N 305 #define inf 0x3f3f3f3f using namespace std; int n,m,s,p; int x[N],y[N],mp[N][N],mx[N][N]; inline int read()int fh=0;char c=getchar();while(!isdigit(c))c=getchar();while(isdigit(c))fh=(fh<<1)+(fh<<3)+(c^48),c=getchar();return fh; int f[5][N][N]; bool valid(int x,int y)return (x>0&&x<=n&&y>0&&y<=m&&mp[x][y]==0); bool can(int k,int x,int y) if(!valid(x-k,y-k)||!valid(x+k,y+k))return false; fr(i,y-k,y+k)if(mp[x-k][i]||mp[x+k][i])return false; fr(i,x-k,x+k)if(mp[i][y-k]||mp[i][y+k])return false; return true; void pre2() fr(i,1,n) fr(j,1,m) int k=0; while(can(k,i,j))k++; mx[i][j]=min(k-1,s); int bs[N][N][2],fx[]=1,0,-1,0,fy[]=0,1,0,-1,dis[20][20][2]; struct nodeint x,y,s1,s2;; #define pr pair<int,int> #define fs first #define sc second queue<pr> q; bool b[N][N]; void bfs(int sx,int sy,int ind) while(!q.empty())q.pop(); fr(i,1,n)fr(j,1,m)bs[i][j][0]=inf,b[i][j]=0; q.push(make_pair(sx,sy));bs[sx][sy][0]=0;bs[sx][sy][1]=0;b[sx][sy]=1; while(!q.empty()) pr tmp=q.front();q.pop(); b[tmp.fs][tmp.sc]=0; fr(i,0,3) int nx=tmp.fs+fx[i],ny=tmp.sc+fy[i]; if(!valid(nx,ny))continue; int ns1=bs[tmp.fs][tmp.sc][0]+1,ns2=bs[tmp.fs][tmp.sc][1]+mx[nx][ny]; if(bs[nx][ny][0]>ns1) bs[nx][ny][0]=ns1;bs[nx][ny][1]=ns2; if(!b[nx][ny])q.push(make_pair(nx,ny)),b[nx][ny]=1; else if(bs[nx][ny][0]==ns1&&bs[nx][ny][1]<ns2) bs[nx][ny][1]=ns2; if(!b[nx][ny])q.push(make_pair(nx,ny)),b[nx][ny]=1; fr(i,0,p)dis[ind][i][0]=bs[x[i]][y[i]][0],dis[ind][i][1]=bs[x[i]][y[i]][1]; const int P=20; int ff[P][1<<P][2]; void hamilton() ++p; fr(i,0,p)fr(j,0,(1<<p)-1)ff[i][j][0]=inf; ff[0][1][0]=ff[0][1][1]=0; fr(i,1,(1<<p)-1)fr(j,0,p) if(i>>j&1) fr(k,0,p) if((i^(1<<j))>>k&1) if(ff[j][i][0]>=ff[k][i^(1<<j)][0]+dis[j][k][0]) if(ff[j][i][0]>ff[k][i^(1<<j)][0]+dis[j][k][0])ff[j][i][1]=ff[k][i^(1<<j)][1]+dis[j][k][1]; else ff[j][i][1]=max(ff[j][i][1],ff[k][i^(1<<j)][1]+dis[j][k][1]); ff[j][i][0]=ff[k][i^(1<<j)][0]+dis[j][k][0]; int ans=1e9,ans2=0; fr(i,0,p-1) if(ans>ff[i][(1<<p)-1][0])ans=ff[i][(1<<p)-1][0],ans2=ff[i][(1<<p)-1][1]; else if(ans==ff[i][(1<<p)-1][0])ans2=max(ans2,ff[i][(1<<p)-1][1]); cout<<ans<<" "<<ans2+mx[x[0]][y[0]]<<endl; bool vis[N]; int ans=1e9,lim; int main() freopen("expand.in","r",stdin); //freopen("expand.out","w",stdout); n=read(),m=read(),s=read(); fr(i,1,n)fr(j,1,m)mp[i][j]=read(); pre2(); x[0]=read()+1,y[0]=read()+1,p=read(); fr(i,1,p)x[i]=read()+1,y[i]=read()+1; fr(i,0,p)bfs(x[i],y[i],i); hamilton(); //solve(); return 0;
正解
#include<bits/stdc++.h> #pragma GCC optimize("O2") #define fr(i,a,b) for(int i=a;i<=b;++i) #define rf(i,a,b) for(int i=a;i>=b;--i) #define min(a,b) (a<b?a:b) #define max(a,b) (a>b?a:b) #define N 305 #define inf 0x3f3f3f3f using namespace std; int n,m,s,p; int x[N],y[N],mp[N][N],mx[N][N]; inline int read()int fh=0;char c=getchar();while(!isdigit(c))c=getchar();while(isdigit(c))fh=(fh<<1)+(fh<<3)+(c^48),c=getchar();return fh; int f[5][N][N]; void pre1() fr(i,1,n)fr(j,1,m) if(!mp[i][j])f[1][i][j]=min(s,min(f[1][i-1][j],min(f[1][i][j-1],f[1][i-1][j-1]))+1); rf(i,n,1)rf(j,m,1) if(!mp[i][j])f[2][i][j]=min(s,min(f[2][i+1][j],min(f[2][i][j+1],f[1][i+1][j+1]))+1); fr(i,1,n)rf(j,m,1) if(!mp[i][j])f[3][i][j]=min(s,min(f[3][i-1][j],min(f[3][i][j+1],f[3][i-1][j+1]))+1); rf(i,n,1)fr(j,1,m) if(!mp[i][j])f[4][i][j]=min(s,min(f[4][i+1][j],min(f[4][i][j-1],f[4][i+1][j-1]))+1); fr(i,1,n)fr(j,1,m) if(!mp[i][j])mx[i][j]=max(0,min(min(f[1][i][j],f[2][i][j]),min(f[3][i][j],f[4][i][j]))-1); bool valid(int x,int y)return (x>0&&x<=n&&y>0&&y<=m&&mp[x][y]==0); bool can(int k,int x,int y) if(!valid(x-k,y-k)||!valid(x+k,y+k))return false; fr(i,y-k,y+k)if(mp[x-k][i]||mp[x+k][i])return false; fr(i,x-k,x+k)if(mp[i][y-k]||mp[i][y+k])return false; return true; void pre2() fr(i,1,n) fr(j,1,m) int k=0; while(can(k,i,j))k++; mx[i][j]=min(k-1,s); int bs[N][N][2],fx[]=1,0,-1,0,fy[]=0,1,0,-1,dis[20][20][2]; struct nodeint x,y,s1,s2;; #define pr pair<int,int> #define fs first #define sc second queue<pr> q; bool b[N][N]; void bfs(int sx,int sy,int ind) while(!q.empty())q.pop(); fr(i,1,n)fr(j,1,m)bs[i][j][0]=inf,b[i][j]=0; q.push(make_pair(sx,sy));bs[sx][sy][0]=0;bs[sx][sy][1]=0;b[sx][sy]=1; while(!q.empty()) pr tmp=q.front();q.pop(); b[tmp.fs][tmp.sc]=0; fr(i,0,3) int nx=tmp.fs+fx[i],ny=tmp.sc+fy[i]; if(!valid(nx,ny))continue; int ns1=bs[tmp.fs][tmp.sc][0]+1,ns2=bs[tmp.fs][tmp.sc][1]+mx[nx][ny]; if(bs[nx][ny][0]>ns1) bs[nx][ny][0]=ns1;bs[nx][ny][1]=ns2; if(!b[nx][ny])q.push(make_pair(nx,ny)),b[nx][ny]=1; else if(bs[nx][ny][0]==ns1&&bs[nx][ny][1]<ns2) bs[nx][ny][1]=ns2; if(!b[nx][ny])q.push(make_pair(nx,ny)),b[nx][ny]=1; // puts(""); // cout<<sx<<" "<<sy<<" "<<ind<<endl; // fr(i,1,n) // fr(j,1,m)cout<<bs[i][j][1]<<" "; // puts(""); // fr(i,0,p)dis[ind][i][0]=bs[x[i]][y[i]][0],dis[ind][i][1]=bs[x[i]][y[i]][1]; const int P=20; int ff[P][1<<P][2]; void hamilton() ++p; fr(i,0,p)fr(j,0,(1<<p)-1)ff[i][j][0]=inf; ff[0][1][0]=ff[0][1][1]=0; fr(i,0,(1<<p)-1)fr(j,0,p) if(i>>j&1) fr(k,0,p-1) if((i^(1<<j))>>k&1) if(ff[j][i][0]>ff[k][i^(1<<j)][0]+dis[j][k][0]) ff[j][i][0]=ff[k][i^(1<<j)][0]+dis[j][k][0]; ff[j][i][1]=ff[k][i^(1<<j)][1]+dis[j][k][1]; else if(ff[j][i][0]==ff[k][i^(1<<j)][0]+dis[j][k][0]) ff[j][i][1]=max(ff[j][i][1],ff[k][i^(1<<j)][1]+dis[j][k][1]); int ans=1e9,ans2=0; fr(i,1,p-1) if(ans>ff[i][(1<<p)-1][0])ans=ff[i][(1<<p)-1][0],ans2=ff[i][(1<<p)-1][1]; else if(ans==ff[i][(1<<p)-1][0])ans2=max(ans2,ff[i][(1<<p)-1][1]); cout<<ans<<" "<<ans2+mx[x[0]][y[0]]<<endl; bool vis[N]; int ans=1e9,lim; inline void dfs(int now,int step,int dist,int sum) if(dist>ans) return; if(step==p) if(dist<ans) ans=dist,lim=sum; else if(dist==ans) lim=max(lim,sum); fr(i,1,p) if(!vis[i]) vis[i]=true; dfs(i,step+1,dist+dis[now][i][0],sum+dis[now][i][1]); vis[i]=false; void solve() fr(i,1,p) vis[i]=true; dfs(i,1,dis[0][i][0],dis[0][i][1]); vis[i]=false; printf("%d %d\n",ans,lim+mx[x[0]][y[0]]); return; int main() freopen("expand.in","r",stdin); freopen("expand.out","w",stdout); n=read(),m=read(),s=read(); fr(i,1,n)fr(j,1,m)mp[i][j]=read(); pre2(); x[0]=read()+1,y[0]=read()+1,p=read(); fr(i,1,p)x[i]=read()+1,y[i]=read()+1; fr(i,0,p)bfs(x[i],y[i],i); //hamilton(); solve(); return 0;
太炸心态了
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