hdu 2883 kebab

It's a network max_flow problem. Make edges from start_point to Task_i. the capacity of this edge is ni * ti ,from Task_i to every time_points,the capacity of this edge is INF,from every time_points to end_point,the capacity of the edge is m.

And then run SAP,You must get answer.

The portal:http://acm.hdu.edu.cn/showproblem.php?pid=2883

#include <cstdio>#include <cstring>#include <memory.h>#include <cstdlib>#include <cmath>const int MAXN = 100010;const int MAXE = 400010;const int INF = 0x3f3f3f3f;struct Edge{    int to,next,cap,flow;}edge[MAXE];int tol;int head[MAXN];int gap[MAXN],dep[MAXN],pre[MAXN],cur[MAXN];void init(){    tol = 0;    memset(head,-1,sizeof(head));}void addedge(int u,int v,int w,int rw = 0){    edge[tol].to = v;edge[tol].cap = w;edge[tol].next = head[u];    edge[tol].flow = 0;head[u] = tol ++;    edge[tol].to = u;edge[tol].cap = rw;edge[tol].next = head[v];    edge[tol].flow = 0;head[v] = tol ++;}int sap(int start,int end,int N){    memset(gap,0,sizeof(gap));    memset(dep,0,sizeof(dep));    memcpy(cur,head,sizeof(head));    int u = start;    pre[u] = -1;    gap[0] = N;    int ans = 0;    while(dep[start] < N){        if(u == end){            int Min = INF;            for(int i= pre[u];i!=-1;i=pre[edge[i^1].to]){                if(Min > edge[i].cap - edge[i].flow)                    Min = edge[i].cap - edge[i].flow;            }            for(int i= pre[u];i!=-1;i=pre[edge[i^1].to]){                edge[i].flow += Min;                edge[i^1].flow -= Min;            }            u = start;            ans += Min;            continue;        }        bool flag = false;        int v;        for(int i=cur[u];i != -1;i = edge[i].next){            v = edge[i].to;            if(edge[i].cap - edge[i].flow && dep[v] + 1 == dep[u]){                flag = true;                cur[u] = pre[v] = i;                break;            }        }        if(flag){            u = v;            continue;        }        int Min = N;        for(int i = head[u];i != -1;i=edge[i].next){            if(edge[i].cap-edge[i].flow && dep[edge[i].to] < Min){                Min = dep[edge[i].to];                cur[u] = i;            }        }        gap[dep[u]]--;        if(!gap[dep[u]]) return ans;        dep[u] = Min + 1;        gap[dep[u]] ++;        if(u != start) u = edge[pre[u]^1].to;    }    return ans;}int flag[1000005];void Deal_with(){    int n,m,numtot,t_max,si,ni,ei,ti,ans;    while(~scanf("%d %d ",&n,&m)){        init();        memset(flag,0,sizeof(flag));        int start_point = 0,t_ans = 0;        numtot = n;        for(int i=1;i<=n;i++){            scanf("%d %d %d %d",&si,&ni,&ei,&ti);            addedge(start_point,i,ni*ti);            t_ans += ni * ti;            si ++;            for(int j = si ;j <= ei; j++){                if(!flag[j]) flag[j] = ++ numtot;                addedge(i,flag[j],INF);            }        }        numtot ++;        int end_point = numtot;        for(int i=1;i<=1000000;i++){            if(flag[i]){                addedge(flag[i],end_point,m);            }        }        ans = sap(start_point,end_point,numtot+1);        //printf("ans : %d t_ ans : %d\n",ans,t_ans);        if(ans == t_ans){            puts("Yes");        }        else{            puts("No");        }    }}int main(void){    //freopen("a.in","r",stdin);    Deal_with();    return 0;}