Cod sursa(job #1892354)

Utilizator ionanghelinaIonut Anghelina ionanghelina Data 24 februarie 2017 22:05:00
Problema Stalpi Scor 80
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.13 kb
#include<bits/stdc++.h>
#define maxN 100005
#define lsb(i) (i&(-i))
#define INF 1000005
using namespace std;
typedef struct tip
{
  int cost,st,dr;
};
tip v[maxN];
int x[maxN],AIB[maxN],n,y,val;
inline int min(int a,int b)
{
    return a<b?a:b;
}
bool cmp(tip a,tip b)
{
    return a.dr<b.dr;
}
void update(int pos,int val)
{
    for(int i=pos;i>=1;i-=lsb(i))
        AIB[i]=min(AIB[i],val);
}
int query(int pos)
{
    int q=INF;
    for(int i=pos;i<=n;i+=lsb(i))
        q=min(q,AIB[i]);
    return q;
}
int main()
{
    freopen("stalpi.in","r",stdin);
    freopen("stalpi.out","w",stdout);
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        scanf("%d%d%d%d",&x[i],&v[i].cost,&v[i].st,&v[i].dr);
        v[i].st=x[i]-v[i].st;
        v[i].dr=x[i]+v[i].dr;
    }
    memset(AIB,INF,sizeof(AIB));
    sort(x+1,x+n+1);
    sort(v+1,v+n+1,cmp);
    for(int i=1;i<=n;i++)
    {
        y=lower_bound(x+1,x+n+1,v[i].st)-x-1;
        val=v[i].cost;
        if(y) val+=query(y);
        y=upper_bound(x+1,x+n+1,v[i].dr)-x-1;
        update(y,val);
    }
    printf("%d\n",AIB[n]);
    return 0;
}