【BZOJ】【刷题合集】【P1066】【P2875】【P1927】【#3】

传送门：

http://www.lydsy.com/JudgeOnline/problem.php?id=1066 最大流

http://www.lydsy.com/JudgeOnline/problem.php?id=2875 矩阵乘法

http://www.lydsy.com/JudgeOnline/problem.php?id=1927 费用流

/*
	ID:zky
	OJ:BZOJ
	Index:1066
	Language:C++
*/
#include<queue>  
#include<vector>  
#include<cstdio>  
#include<cstring>  
#include<climits>  
#include<iostream>  
#include<algorithm>  
#define clear(x) memset(x,0,sizeof(x))  
#define inf(x) memset(x,0x7f,sizeof(x))  
#define Size G[u].size()  
#define read3(x,y,z) scanf("%d%d%d",&x,&y,&z)  
#define read4(x,y,z,w) scanf("%d%d%d%d",&x,&y,&z,&w)  
using namespace std;  
int s,t;  
int n,m,k;  
const int INF=INT_MAX;  
struct edge{  
    int u,v,cap,flow;  
};  
vector<edge>edges;  
vector<vector<int> >G;  
int d[1001];  
int cur[1001];  
int vis[1001];  
int prev[1001];  
void add(int u,int v,int cap){  
    edges.push_back((edge){u,v,cap,0});  
    G[u].push_back(edges.size()-1);  
    edges.push_back((edge){v,u,0,0});  
    G[v].push_back(edges.size()-1);  
}  
bool bfs(){  
    clear(d);clear(vis);  
    queue<int>q;  
    q.push(s);  
    vis[s]=1;  
    while(!q.empty()){  
        int u=q.front();q.pop();  
        for(int i=0;i<Size;i++){  
            edge &e=edges[G[u][i]];  
            if(!vis[e.v]&&e.cap>e.flow){  
                vis[e.v]=1;  
                d[e.v]=d[u]+1;  
                q.push(e.v);      
            }  
        }  
    }  
    return vis[t];  
}  
int dfs(int x,int a){  
    if(x==t||a==0)return a;  
    int flow=0,f;  
    for(int &i=cur[x];i<G[x].size();i++){  
        edge &e=edges[G[x][i]];  
        if(d[e.v]==d[x]+1&&(f=dfs(e.v,min(a,e.cap-e.flow)))>0){  
            flow+=f;  
            e.flow+=f;  
            edges[G[x][i]^1].flow-=f;  
            a-=f;  
            if(!a)break;  
        }  
    }  
    return flow;  
}  
int Dinic(){  
    int flow=0;  
    while(bfs()){  
        clear(cur);  
        int x;  
        while(x=dfs(s,INF)){  
            flow+=x;  
        }  
        //flow+=dfs(s,INF);  
    }  
    return flow;
	//cout<<flow<<" ";  
}
int r,c,D,sum=0;
int map[21][21];
int map2[21][21];
int main(){
	cin>>r>>c>>D;
	G.resize(r*c*2+10);
	s=0;t=r*c*2+1;
	string str;
	int hash[21][21];
	int tot=0;
	for(int i=1;i<=r;i++)
	for(int j=1;j<=c;j++)
	hash[i][j]=++tot;
	for(int i=1;i<=r;i++){
		cin>>str;
		for(int j=1;j<=c;j++)
		map[i][j]=str[j-1]-'0';
	}
	for(int i=1;i<=r;i++){
		cin>>str;
		for(int j=1;j<=c;j++){
			if(str[j-1]=='L'){
				map2[i][j]=1;
				sum++;
				add(s,hash[i][j],1);
			}
		}
	}
	for(int i=1;i<=r;i++)
	for(int j=1;j<=c;j++){
		if(!map[i][j])continue;
		add(hash[i][j],hash[i][j]+tot,map[i][j]);
		for(int dx=-D;dx<=D;dx++)
		for(int dy=-D;dy<=D;dy++){
			int x=i+dx,y=j+dy;
			if(abs(dx)+abs(dy)<=D&&x>=1&&y>=1&&x<=r&&y<=c&&map[i][j]&&map[x][y])
			add(hash[i][j]+tot,hash[x][y],INF);	
			if(abs(dx)+abs(dy)<=D&&(x<1||y<1||x>r||y>c)&&map[i][j])	
			add(hash[i][j]+tot,t,INF);		
		}
	}
	int deb=0;
	if(deb)
	for(int i=0;i<edges.size();i++)if(i%2==0)
	printf("#%d  %d -> %d  cap:%d\n",
			i,edges[i].u,edges[i].v,edges[i].cap);
	cout<<sum-Dinic()<<endl;
	return 0;
}  

/*
	ID:zky
	OJ:BZOJ
	Index:2875
	Language:C++
*/
#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
typedef unsigned long long lld;
lld m,a,c,x0,n,g;
lld Mul(lld x,lld y,lld m){
	if(y==0)return 0;
	if(y==1)return x%m;
	lld res;
	res=Mul(x,y>>1,m);
	if((y&1)==1)return (res+res+x)%m;
	else return (res+res)%m;
}
struct Matrix{
	lld a[2][2];
	Matrix operator*(const Matrix &x)const{
		Matrix res;
		res.a[0][0]=Mul(a[0][0],x.a[0][0],m)+Mul(a[0][1],x.a[1][0],m);
		res.a[0][1]=Mul(a[0][0],x.a[0][1],m)+Mul(a[0][1],x.a[1][1],m);
		res.a[1][0]=Mul(a[1][0],x.a[0][0],m)+Mul(a[1][1],x.a[1][0],m);
		res.a[1][1]=Mul(a[1][0],x.a[0][1],m)+Mul(a[1][1],x.a[1][1],m);
		return res;			
		/*00 00 01 10
		00 01 01 11
		10 00 11 10
		10 01 11 11*/
	}
	Matrix operator%(const lld &p){
		a[0][0]%=p;a[0][1]%=p;
		a[1][0]%=p;a[1][1]%=p;
		return *this;
	}
	Matrix(){
		a[0][0]=1;a[0][1]=0;
		a[1][0]=0;a[1][1]=1;
	}
};
lld mul(Matrix x,lld f1,lld f2,lld mod){
	lld g=mod;
	return (Mul(x.a[0][0],f1,mod)+Mul(x.a[0][1],f2,mod))%mod;
}

Matrix power(Matrix a,lld k,lld p){
	Matrix x;
	if(k==0)return x;
	x=x%p*(power(a,k/2,p)%p)%p;
	x=(x%p)*(x%p)%p;
	if(k&1)x=x*(a%p)%p;
	return x;
}
int main(){	
	cin>>m>>a>>c>>x0>>n>>g;
	Matrix x;
	x.a[0][0]=a;x.a[0][1]=1;
	x.a[1][0]=0;x.a[1][1]=1;
	x=x%m;
	x=power(x,n,m)%m;
	cout<<mul(x,x0,c,m)%m%g<<endl;
	return 0;
}

/*
	ID:zky
	OJ:BZOJ
	Index:1927
	Language:C++
*/
#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
#include<queue>  
#include<vector>  
#include<cstdio>  
#include<cstring>  
#include<climits>  
#include<iostream>  
#include<algorithm>  
#define clear(x) memset(x,0,sizeof(x))  
#define inf(x) memset(x,0x7f,sizeof(x))  
#define Size G[u].size()  
#define read3(x,y,z) scanf("%d%d%d",&x,&y,&z)  
#define read4(x,y,z,w) scanf("%d%d%d%d",&x,&y,&z,&w)  
using namespace std;  
int s,t;  
int n,m,k;  
const int INF=INT_MAX;  
struct edge{  
    int u,v,cap,flow,cost;  
};  
vector<edge>edges;  
vector<vector<int> >G;  
int d[3001];  
int cur[3001];  
int vis[3001];  
int prev[3001];  
void add(int u,int v,int cap,int cost){  
    edges.push_back((edge){u,v,cap,0,cost});  
    G[u].push_back(edges.size()-1); 
    edges.push_back((edge){v,u,0,0,-cost});  
    G[v].push_back(edges.size()-1); 	 
}  
int a[3001];  
bool spfa(int  &flow,int &cost){  
    queue<int>q;  
    q.push(s);  
    memset(d,0x7f,sizeof(d));  
    memset(vis,0,sizeof(vis));  
    int B=d[0];  
    d[s]=0;  
    vis[s]=1;  
    a[s]=INF;  
    while(!q.empty()){  
        int u=q.front();q.pop();vis[u]=0;  
        for(int i=0;i<G[u].size();i++){  
            edge &e=edges[G[u][i]];  
            if(e.cap-e.flow>0&&d[e.v]>d[u]+e.cost){  
                d[e.v]=d[u]+e.cost;  
                prev[e.v]=G[u][i];  
                a[e.v]=min(a[u],e.cap-e.flow);  
                if(!vis[e.v]){  
                    vis[e.v]=1;  
                    q.push(e.v);  
                }  
            }  
        }  
    }  
    if(d[t]==B)return false;  
    int u=t;  
    flow+=a[t];  
    cost+=a[t]*d[t];  
    while(u!=s){  
        edges[prev[u]].flow+=a[t];  
        edges[prev[u]^1].flow-=a[t];  
        u=edges[prev[u]].u;  
    }  
    return true;  
}  
int flow,cost;
void costflow(){  
    flow=0;cost=0;  
    while(spfa(flow,cost));  
    cout<<cost<<endl;  
}  
//int a[888];
int main(){
	cin>>n>>m;
	G.resize(n*2+10);
	s=0;t=2*n+1;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		add(s,i+n,1,a[i]);
	}
	for(int i=1;i<=m;i++){
		int u,v,w;
		read3(u,v,w);
		if(u>v)swap(u,v);
		add(u,v+n,1,w);
	}
	for(int i=1;i<=n;i++){
		add(s,i,1,0);
		add(i+n,t,1,0);
	}
	costflow();
	return 0;
}