HDU2883.kebab

来源：互联网发布：淘宝登录页面网页制作编辑：程序博客网时间：2024/05/22 10:33
//因为时间的开始结束范围跨度较大,所以离散化#include <map>#include <set>#include <stack>#include <queue>#include <cmath>#include <ctime>#include <vector>#include <cstdio>#include <cctype>#include <cstring>#include <cstdlib>#include <iostream>#include <algorithm>using namespace std;#define INF 0x3f3f3f3f#define inf -0x3f3f3f3f#define lson k<<1, L, mid#define rson k<<1|1, mid+1, R#define mem0(a) memset(a,0,sizeof(a))#define mem1(a) memset(a,-1,sizeof(a))#define mem(a, b) memset(a, b, sizeof(a))typedef long long ll;const int maxn=1000 + 10;struct Edge{    int from,to,cap,flow;    Edge(int u,int v,int c,int f):from(u),to(v),cap(c),flow(f){}};struct Dinic{    int n,m,s,t;                        //结点数,边数（包括反相弧），源点编号和汇点编号    vector<Edge>edges;                    //边表，edges[e]和edges[e^1]互为反相弧    vector<int>G[maxn];                    //邻接表，G[i][j]表示结点i的第j条边在e数组中的序号    bool vis[maxn];                        //BFS使用    int d[maxn];                        //从起点到i的距离    int cur[maxn];                        //当前弧下标    void AddEdge(int from,int to,int cap){        edges.push_back(Edge(from,to,cap,0));        edges.push_back(Edge(to,from,0,0));        m=edges.size();        G[from].push_back(m-2);        G[to].push_back(m-1);    }    void init(int n){        this->n=n;        for(int i=0;i<=n;i++)            G[i].clear();        edges.clear();    }    bool BFS(){        mem0(vis);        queue<int>Q;        Q.push(s);        d[s]=0;        vis[s]=1;        while(!Q.empty()){            int x=Q.front();            Q.pop();            for(int i=0;i<G[x].size();i++){                    //只考虑残量网络中的弧                Edge& e=edges[G[x][i]];                if(!vis[e.to]&&e.cap>e.flow){                    vis[e.to]=1;                    d[e.to]=d[x]+1;                    Q.push(e.to);                }            }        }        return vis[t];    }    ll DFS(int x,int a){        if(x==t||a==0)            return a;        ll flow=0,f;        for(int& i=cur[x];i<G[x].size();i++){            Edge& e=edges[G[x][i]];            if(d[x]+1==d[e.to]&&(f=DFS(e.to,min(a,e.cap-e.flow)))>0){                e.flow+=f;                edges[G[x][i]^1].flow-=f;                flow+=f;                a-=f;                if(a==0)                    break;            }        }        return flow;    }    ll Maxflow(int s,int t){        this->s=s;        this->t=t;        ll flow=0;        while(BFS()){            mem0(cur);            flow+=DFS(s,INF);        }        return flow;    }};Dinic solve;struct node{    int si,ei;}a[maxn];int time1[3001];int main(){    int x,y,z;    int n,m;    while(scanf("%d%d",&n,&m)==2){        solve.init(3*n+2);              //初始化        int num;        int ti;        int cnt=0;        ll full_flow=0;        //printf("PPPPPP\n");        for(int i=1;i<=n;i++){            scanf("%d%d%d%d",&a[i].si,&num,&a[i].ei,&ti);            solve.AddEdge(0,i,num*ti);            time1[cnt++]=a[i].si;            time1[cnt++]=a[i].ei;            full_flow+=num*ti;        }        sort(time1,time1+cnt);        for(int i=1;i<=n;i++)            for(int j=0;j<cnt;j++){                if(a[i].si<=time1[j]&&a[i].ei>=time1[j+1])                    solve.AddEdge(i,n+j+1,INF);            }        //printf("PPPPPP\n");        int t=3*n+2;        for(int i=0;i<cnt;i++)            solve.AddEdge(i+n+1,t,(time1[i+1]-time1[i])*m);        ll tmp=solve.Maxflow(0,t);        if(tmp==full_flow)            printf("Yes\n");        else            printf("No\n");    }    return 0;}
0 0