Codeforce 527D Clique Problem题解

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<iostream>
#include<algorithm>
using namespace std;
#define MAXN 200001
struct LINE{int l,r;}a[MAXN];
int N,ans=0;
bool cmp(LINE A,LINE B){return A.r<B.r;}
int main()
{
scanf("%d",&N);
for(int i=1;i<=N;i++)
{
int X,W;
scanf("%d%d",&X,&W);
a[i].l=X-W;
a[i].r=X+W;
}
sort(a+1,a+1+N,cmp);
int now=a[1].r;ans=1;
for(int i=2;i<=N;i++)
if(a[i].l>=now)
{
ans++;
now=a[i].r;
}
printf("%d\n",ans);
return 0;
}