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| #include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
using namespace std;
#define int ll
#define REP(i,e,s) for(register int i=e; i<=s; i++)
#define DREP(i,e,s) for(register int i=e; i>=s; i--)
#define ll long long
#define DE(...) fprintf(stderr,__VA_ARGS__)
#define DEBUG(a) DE("DEBUG: %d\n",a)
#define file(a) freopen(a".in","r",stdin);freopen(a".out","w",stdout)
int read() {
int x=0,f=1,ch=getchar();
while(ch>'9'||ch<'0'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
return x*f;
}
const int MAXN=5000000+10,INF=0x3f3f3f3f3f3f;
struct work {
int s,v;
} a[MAXN];
bool cmp(work a,work b) {
return a.s<b.s;
}
int jian[MAXN],far[MAXN],qianz[MAXN];
signed main() {
int n=read();
REP(i,1,n) {
a[i].s=read();
a[i].v=read();
}
sort(a+1,a+1+n,cmp);
REP(i,1,n) qianz[i]=qianz[i-1]+a[i].v;
if(0&&n<=5000) {
int ans=0;
REP(i,1,n) REP(j,i,n) {
ans=max(ans,qianz[j]-qianz[i-1]+a[i].s-a[j].s);
}
printf("%lld\n",ans);
return 0;
}
int sum=0;
DREP(i,n,1) {
jian[i]=-a[i].s-sum;
sum+=a[i].v;
}
far[n]=n;
DREP(i,n-1,1) {
if(jian[i]>jian[far[i+1]]) far[i]=i;
else far[i]=far[i+1];
}
int ans=0;
REP(i,1,n) {
int l=i,r=far[i];
ans=max(ans,qianz[r]-qianz[l-1]+a[l].s-a[r].s);
}
printf("%lld\n",ans);
return 0;
}
|
