求助：WA第一个点

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
using namespace std;
typedef long long LL;
const LL inf=1LL<<62;
const int N=500000;

	int n,d,x[N+3];
	LL k,s[N+3],f[N+3];
	
bool chk(int g){
	for(int i=1;i<=n;i++)
		f[i]=-inf;
	f[0]=0;
	for(int i=0;i<=n;i++)
	if(f[i]!=-inf){
		int j;
		for(j=i+1;x[j]<x[i]+(d-g)&&j<=n
				&&x[j]<=x[i]+(d+g);j++);
		for(;x[j]<=x[i]+(d+g)&&j<=n;j++)
			f[j]=max(f[j],f[i]+s[j]);
			
	}
	
	LL tmp=-inf;
	for(int i=1;i<=n;i++)
		tmp=max(tmp,f[i]);
		
	return tmp>=k;
	
}

int main(){
	scanf("%d%d%lld",&n,&d,&k);
	for(int i=1;i<=n;i++)
		scanf("%d%lld",&x[i],&s[i]);
		
	int maxd=x[1];
	for(int i=2;i<=n;i++)
	    maxd=max(maxd,x[i]-x[i-1]);
	
	x[0]=0;
	int l=0,r=maxd,mid,ans=-1;
	while(l<=r){
		mid=(l+r)>>1;
		if(chk(mid)){
			ans=mid;
			r=mid-1;
			
		}
		else 
			l=mid+1;
		
	}
	
	printf("%d",ans);
	
	return 0;
	
}