HDU 4122 Alice's mooncake shop (line segment tree)

Question:

The cost of mooncakes made by a mooncake store varies by hour.

How long does it take to save it for money. Ask you the minimum cost for completing all orders.

Train of Thought Analysis:

Ans = segma (Num [] * (cost [] + (I-j) * s ))

After sorting it out, we will find that the formula is

Cost []-J * s + I * s

For each order, we take out the I for analysis.

Therefore, we use cost-J * s to build a new one.

Find the minimum cost during storage.

#include <cstdio>#include <iostream>#include <algorithm>#include <cstring>#include <string>#define lson num<<1,s,mid#define rson num<<1|1,mid+1,e#define maxn 2555#define maxm 100005#define inf 0x3f3f3f3fusing namespace std;typedef long long LL;int n,m;int days[2][13]={{0,31,28,31,30,31,30,31,31,30,31,30,31},                {0,31,29,31,30,31,30,31,31,30,31,30,31}};string tab[] = {"","Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"};LL tre[maxm<<2];int getmonth(string x){    for(int i=1;i<=12;i++)    if(x==tab[i])return i;}bool leap(int x){    if(((x%4==0) && x%100!=0) || x%400==0)return true;    return false;}LL gethour(int month,int day,int year,int hour){    LL res=day-1;    int is=leap(year);    for(int i=1;i<month;i++)res+=days[is][i];    for(int i=2000;i<year;i++)    res+=365+leap(i);    res*=24;    res+=hour+1;    return res;}void build(int num,int s,int e){    tre[num]=inf;    if(s==e)return;    int mid=(s+e)>>1;    build(lson);    build(rson);}void update(int num,int s,int e,int pos,LL val){    if(s==e)    {        tre[num]=val;        return;    }    int mid=(s+e)>>1;    if(pos<=mid)update(lson,pos,val);    else update(rson,pos,val);    tre[num]=min(tre[num<<1],tre[num<<1|1]);}LL query(int num,int s,int e,int l,int r){    if(l<=s && r>=e)    {        return tre[num];    }    int mid=(s+e)>>1;    if(r<=mid)return query(lson,l,r);    else if(l>mid)return query(rson,l,r);    else return min(query(lson,l,mid),query(rson,mid+1,r));}string tmp;LL num[maxn];LL cost[maxm];LL time[maxm];int main(){    while(cin>>n>>m)    {        if(n==0 && m==0)break;        for(int i=1;i<=n;i++)        {            int d,y,h,Num;            cin>>tmp;            cin>>d>>y>>h>>Num;            num[i]=Num;            time[i]=gethour(getmonth(tmp),d,y,h);        }        LL S,T;        build(1,1,m);        cin>>T>>S;        for(int i=1;i<=m;i++)        {            cin>>cost[i];            cost[i]-=i*S;            update(1,1,m,i,cost[i]);        }        LL ans=0;        for(int i=1;i<=n;i++)        {            if(time[i]>m)break;            ans+=num[i]*(query(1,1,m,max(1LL,time[i]-T+1),time[i])+time[i]*S);        }        cout<<ans<<endl;    }    return 0;}