Codeforces Round #433 (Div. 2) D. Jury Meeting

题目大意

所有人要去0号城市，并且只坐飞机，飞机只有去0的和从0出发的，所有人要呆k天，问最小机票花费。

题解

对去的和返回的飞机分类排序，去的从早到晚，回来的从晚到早，处理每个时间上所有人去0的最小代价（由于排好序，所以选择时选的是时间最小的），从晚到早选返回的，所有人都满足时算一下代价，最后找出代价最小值。

#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>using namespace std;int read(){    char ch=getchar();int f=0;    while(ch<'0'||ch>'9') ch=getchar();    while(ch>='0'&&ch<='9') {f=f*10+(ch^48);ch=getchar();}    return f;}struct data{    int cost;    int pla;    int tim;}come[100005],leave[100005];int tot1,tot2,val[100005],finish_time,cou,val2[100005],cou2,finish_time2;long long sum,finish[1000005],sum2,ans=900000000000000000LL;bool cmp(data x,data y){    return x.tim<y.tim;}bool cmp2(data x,data y){    return x.tim>y.tim;}int main(){    int n=read(),m=read(),k=read();    for(int i=1;i<=m;i++)    {        int d=read(),f=read(),t=read(),c=read();        if(f==0)        {            leave[++tot1].pla=t;            leave[tot1].cost=c;            leave[tot1].tim=d;        }        else if(t==0)        {            come[++tot2].pla=f;            come[tot2].cost=c;            come[tot2].tim=d;        }    }    sort(come+1,come+tot2+1,cmp);    sort(leave+1,leave+tot1+1,cmp2);    for(int i=1;i<=tot2;i++)    {        if(!val[come[i].pla])        {            val[come[i].pla]=come[i].cost;            sum+=come[i].cost;            cou++;            if(cou==n)            {                finish_time=come[i].tim;                finish[come[i].tim]=sum;            }        }        else        {            if(come[i].cost>=val[come[i].pla])            continue;            sum+=come[i].cost;            sum-=val[come[i].pla];            val[come[i].pla]=come[i].cost;            if(cou==n)            {                finish[come[i].tim]=sum;            }        }    }    for(int i=finish_time;i<=1000000;i++)    {        if(finish[i]==0)        finish[i]=finish[i-1];    }    //for(int i=1;i<=20;i++)//  cout<<finish[i]<<" ";    for(int i=1;i<=tot1;i++)    {        if(finish_time+k+1>leave[i].tim)        break;        if(!val2[leave[i].pla])        {            cou2++;            val2[leave[i].pla]=leave[i].cost;            sum2+=leave[i].cost;            if(cou2==n&&finish_time+k<=leave[i].tim)            {                ans=min(ans,sum2+finish[leave[i].tim-k-1]);            }        }        else        {            if(leave[i].cost>=val2[leave[i].pla])            continue;            sum2+=leave[i].cost;            sum2-=val2[leave[i].pla];            val2[leave[i].pla]=leave[i].cost;            if(cou2==n)            {                ans=min(ans,sum2+finish[leave[i].tim-k-1]);            }        }    }    if(ans==900000000000000000LL||!finish_time||cou2!=n||cou!=n)    puts("-1");    else cout<<ans;}