Submission #977859

#	Time	Username	Problem	Language	Result	Execution time	Memory
977859		vjudge1	Cake 3 (JOI19_cake3)	C11	100 / 100	464 ms	6740 KiB

cake3

#include<stdio.h>
#include<time.h>
#include<stdlib.h>

#define N 200000
int n, M, v[N],c[N],o[N],v2[N],vm[N],fw[N];
long long fw2[N],z=-1e18;

void add_(int p,int k1,long long k2) { for(;p<N;p|=p+1)fw[p]+=k1,fw2[p]+=k2; }
long long search()
{
    long long val2=0;int val=0,pos=0;
    for(int j=1<<20;j>>=1;)
        if(pos+j<=N&&val+fw[pos+j-1]<=M)pos+=j,val+=fw[pos-1],val2+=fw2[pos-1];
    return val2;
}

int cl=0,cr=-1;
void add(int i) { add_(vm[i],1,v[i]); }
void del(int i) { add_(vm[i],-1,-v[i]); }
void move(int l,int r)
{
    while(cr<r)add(++cr);
    while(cl>l)add(--cl);
    while(cr>r)del(cr--);
    while(cl<l)del(cl++);
}

void map(int i)
{
    int lb=-1,ub=n,x=v[i];
    while(ub-lb>1)
    {
        int mid=lb+(ub-lb)/2;
        if(v2[mid]<x)lb=mid;
        else ub=mid;
    }
    vm[i]=n-ub-1;
}

void sort(int *a,int l,int r)
{
    while(l<r)
    {
        int i=l,j=l,k=r,t,p=a[l+rand()%(r-l)];
        while(j<k)
        {
            int cmp;
            if(a==v2)cmp=a[j]-p;
            else cmp=c[a[j]]-c[p];
            if(cmp<0)
                t=a[i],a[i]=a[j],a[j]=t,++i,++j;
            else if(cmp==0)
                ++j;
            else
                t=a[--k],a[k]=a[j],a[j]=t;
        }
        sort(a,l,i);
        l=k;
    }
}

void dnc(int l,int r,int optl,int optr)
{
    if(l>r) return;
    int m=l+(r-l)/2,opt=-1;
    long long res=-1e18,res2;
    for(int i=optl;i<=optr&&i+M-1<=m;++i)
    {
        move(i,m);
        res2=search()-2*(c[m]-c[i]);
        if(res2>res)res=res2,opt=i;
    }
    if(res>z)z=res;
    dnc(l,m-1,optl,opt);
    dnc(m+1,r,opt,optr);
}

int main()
{
    srand(time(0));
    scanf("%d%d",&n,&M);
    for(int i=0;i<n;++i)scanf("%d%d",v+i,c+i),o[i]=i;
    sort(o,0,n);
    for(int i=0;i<n;++i)v2[i]=v[o[i]],vm[i]=c[o[i]];
    for(int i=0;i<n;++i)c[i]=vm[i],v[i]=v2[i],o[i]=0;
    sort(v2,0,n);
    for(int i=0;i<n;++i)
    {
        map(i);
        /* duplicate element break fenwick search */
        vm[i]-=o[vm[i]]++;
    }
    dnc(M-1,n-1,0,n-1);
    printf("%lld",z);
}

Compilation message (stderr)

cake3.c: In function 'main':
cake3.c:82:5: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |     scanf("%d%d",&n,&M);
      |     ^~~~~~~~~~~~~~~~~~~
cake3.c:83:25: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |     for(int i=0;i<n;++i)scanf("%d%d",v+i,c+i),o[i]=i;
      |                         ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 19 / 19
• Subtask 3: 76 / 76