Submission #952184

#	Time	Username	Problem	Language	Result	Execution time	Memory
952184		sleepntsheep	Lightning Rod (NOI18_lightningrod)	C11	0 / 100	46 ms	7504 KiB

Main

unsigned X=12345;int rand_(){return(X*=3)/2;}
int(*compar)(int,int);
void sort(int*aa,int l,int r)
{
    while(l<r)
    {
        int i=l,j=l,k=r,t,p=aa[l+rand_()%(r-l)];
        while(j<k)
            switch(compar(aa[j],p))
            {
                case 0:++j;break;
                case -1:t=aa[j],aa[j]=aa[i],aa[i]=t,++i,++j;break;
                case 1:t=aa[--k],aa[k]=aa[j],aa[j]=t;break;
            }
        sort(aa,l,i);
        l=k;
    }
}

#include<stdio.h>


#define N 200005
int n,x[N],y[N],o[N],z,far;

int c(int i,int j)
{
    if(x[i]==x[j])return y[i]>y[j]?-1:y[i]<y[j]?1:0;
    return x[i]<x[j]?-1:x[i]>x[j]?1:0;
}

int main()
{
    scanf("%d",&n);
    for(int i=0;i<n;++i)
    {
        scanf("%d%d",x+i,y+i),o[i]=i;
        int t=x[i];
        x[i]=t-y[i];
        y[i]=t+y[i];
    }
    compar=c;
    sort(o,0,n);
    for(int i=0;i<n;++i)
    {
        if(far>=y[o[i]])
            ;
        else
            far=y[o[i]],++z;
    }
    printf("%d",z);
}

Compilation message (stderr)

lightningrod.c: In function 'main':
lightningrod.c:34:5: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |     scanf("%d",&n);
      |     ^~~~~~~~~~~~~~
lightningrod.c:37:9: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         scanf("%d%d",x+i,y+i),o[i]=i;
      |         ^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 4
• Subtask 2: 0 / 7
• Subtask 3: 0 / 12
• Subtask 4: 0 / 21
• Subtask 5: 0 / 26
• Subtask 6: 0 / 10
• Subtask 7: 0 / 20