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ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#209523 | #6327. Count Arithmetic Progression | ucup-team870 | TL | 0ms | 0kb | C++14 | 3.7kb | 2023-10-10 15:32:05 | 2023-10-10 15:32:05 |
answer
#include <bits/stdc++.h>
#define rep(i,l,r) for(int i=l; i<=r; i++)
#define per(i,r,l) for(int i=r; i>=l; i--)
#define IOS {cin.tie(0);cout.tie(0);ios::sync_with_stdio(0);}
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
#define lll __int128
#define int long long
const int N = 300030,mod=998244353;
const ll inf=1e12+5;
int L[N], R[N];
struct node {
ll x, y;
node (ll _x = 0, ll _y = 0) {x = _x, y = _y;}
} st[N], a[N], b[N];
ll operator ^ (node a, node b) {return 1ll * a.x * b.y - 1ll * b.x * a.y; }
node operator - (node a, node b) {return node(a.x-b.x, a.y-b.y);}
void build1(node *a, int &n) {
int top = 0;
rep (i, 1, n) {
while (top > 1 && ((st[top] - st[top-1]) ^ (a[i] - st[top-1])) <= 0) top--;
st[++top] = a[i];
}
rep (i, 1, top) a[i] = st[i];
n = top;
}
void build2(node *a, int &n) {
int top = 0;
rep (i, 1, n) {
while (top > 1 && ((st[top] - st[top-1]) ^ (a[i] - st[top-1])) >= 0) top--;
st[++top] = a[i];
}
rep (i, 1, top) a[i] = st[i];
n = top;
}
ll flr(ll x,ll y){
if(x>=0)return x/y;
ll v=x/y; return v-(v*y!=x);
}
struct fs{
ll fz,fm;
bool operator < (const fs&t)const &{
assert(fm>0 && t.fm>0);
return fz*t.fm<fm*t.fz;
};
bool operator <= (const fs&t)const &{
assert(fm>0 && t.fm>0);
return fz*t.fm<=fm*t.fz;
};
ll fl(){
return flr(fz,fm);
}
ll cl(){
return flr(fz-1,fm);
}
ll cel(){
if(fz>=0)return (fz-1)/fm+1;
return fz/fm;
}
};
pair<fs,int>q[N*2];
fs q1[N],q2[N];
signed main() {
int n; scanf("%d", &n);
rep (i, 1, n) {
scanf("%d", &L[i]);
}
rep (i, 1, n) {
scanf("%d", &R[i]);
}
rep (i, 1, n) {
a[i] = node(i, R[i]);
b[i] = node(i, L[i]);
}
int s1 = n, s2 = n;
build1(a, s1);
// rep(i,1,s1)cout<<a[i].x<<' '<<a[i].y<<'\n';
build2(b, s2);
// rep(i,1,s2)cout<<b[i].x<<' '<<b[i].y<<'\n';
rep(i,2,s1)q1[i]={a[i].y-a[i-1].y , a[i].x-a[i-1].x};
rep(i,2,s1-1)assert(q1[i]<=q1[i+1]);
rep(i,2,s2)q2[i]={b[i].y-b[i-1].y , b[i].x-b[i-1].x};
rep(i,2,s2-1)assert(q2[i+1]<=q2[i]);
int cnt=0;
q[++cnt]={{-inf,1},0}; q[++cnt]={{inf,1},0};
rep(i,2,s1)q[++cnt]={q1[i],1};
rep(i,2,s2)q[++cnt]={q2[i],-1};
sort(q+1,q+cnt+1);
// rep(i,1,cnt){
// cout<<q[i].first.fz<<" "<<q[i].first.fm<<' '<<q[i].second<<'\n';
// }
int i1=1,i2=s2;
auto cal=[&](ll L,ll R){
// cout<<L<<" "<<R<<" "<<i1<<" "<<i2<< '\n';
if(L>R)return 0ll;
ll k1=-a[i1].x,b1=a[i1].y; ll k2=-b[i2].x,b2=b[i2].y;
// swap(k1,k2); swap(b1,b2);
// cout<<i1<<' '<<i2<<" "<< L<<" "<<R<<" "<<k1<<" "<<b1<<" "<<k2<<" "<<b2<<'\n';
lll len=R-L+1;
if(k1==k2){
return (ll)(len*max(0ll,b1-b2+1)%mod);
}
ll d=k1-k2,fz=b2-b1;
ll l=-inf,r=inf;
if(d<0){
d=-d;fz=-fz; r=min(r,fs{fz,d}.fl());
}
else l=max(l,fs{fz,d}.cel());
// cout<<l<<' '<<r<<'\n';
L=max(L,l); R=min(R,r);
if(L>R)return 0ll;
len=R-L+1;
return (ll)((b1-b2+1)*len+(k1-k2)*len*(L+R)/2)%mod;
};
ll ans=0;
ans+=cal(q[1].first.cel(),q[2].first.cl());
// cout<<cal(q[1].first.cel(),q[2].first.cl())<<'\n';
assert(q[1].second==0 && q[cnt].second==0);
rep(i,2,cnt-1){
if(q[i].second==1)++i1;
else --i2;
ans=(ans+cal(q[i].first.cel(),q[i+1].first.cl()))%mod;
// cout<<cal(q[i].first.cel(),q[i+1].first.cl())<<'\n';
}
cout<<ans<<'\n';
}
/*
3
5 5 2
7 6 7
*/
详细
Test #1:
score: 0
Time Limit Exceeded
input:
3 5 5 2 7 6 7