Submission #1168608

#	Time	Username	Problem	Language	Result	Execution time	Memory
1168608		son2008	Road Construction (JOI21_road_construction)	C++20	100 / 100	2666 ms	17160 KiB

road_construction

#include<bits/stdc++.h>
using namespace std;
#define task "task"
#define ii pair<int,int>
#define fi first
#define se second
#define int long long
#define ll long long
#define ld double
#define mp make_pair
#define lg2 30
#define iii pair<int,ii>
#define iiii pair<ii,ii>
#define base 29
#define eps 1e-8
int dx[]= {0LL,0LL,1,-1,1,1,-1,-1};
int dy[]= {1,-1,0LL,0LL,1,-1,1,-1};
const int maxn=3e5+5;
const int mod=1e9+7;
int n,k,neny[maxn];
vector<int>nen;
struct pt
{
    int x,y;
};
pt a[maxn];
bool cmp(pt x,pt y)
{
    return x.x<y.x;
}
struct FEN
{
    int n;
    vector<int>bit;
    FEN(){};
    FEN(int _n):bit(n+1,0),n(_n+1)
    {
    };
    int get(int r) {
        int ret = 0;
        for (; r >= 0; r = (r & (r + 1)) - 1)
            ret += bit[r];
        return ret;
    }

    int get(int l, int r) {
        return get(r) - get(l - 1);
    }

    void update(int idx, int delta) {
        for (; idx < n; idx = idx | (idx + 1))
            bit[idx] += delta;
    }
    void updateRange(int l,int r,int val)
    {
        update(l,val);
        update(r+1,-val);
    }
}bit;
//max(x[i]-x[j],|y[i]-y[j]|)
bool check(int mid)
{
    bit=FEN(n+1);
    int l=1;
    int cnt=0;
    for(int i=1;i<=n;i++)
    {
        while(true)
        {
            if(i==l||a[i].x-a[l].x<=mid)break;
            bit.update(neny[l],-1);
            l++;
        }
        int L=lower_bound(nen.begin(),nen.end(),a[i].y-mid)-nen.begin();
        int R=upper_bound(nen.begin(),nen.end(),a[i].y+mid)-nen.begin();
        cnt+=bit.get(R)-bit.get(L);
        bit.update(neny[i],+1);
    }
    return cnt>=k;
}
void init()
{
    cin>>n>>k;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i].x>>a[i].y;
        a[i]={a[i].x+a[i].y,a[i].x-a[i].y};
        nen.push_back(a[i].y);
    }
    sort(a+1,a+n+1,cmp);
    sort(nen.begin(),nen.end());
    nen.erase(unique(nen.begin(),nen.end()),nen.end());
    for(int i=1;i<=n;i++)
    {
        neny[i]=lower_bound(nen.begin(),nen.end(),a[i].y)-nen.begin()+1;
    }
}
void process()
{
    int l=0,r=4e9,ans=0;
    while(l<=r)
    {
        int mid=(l+r)/2;
        if(check(mid))
        {
            ans=mid;
            r=mid-1;
        }
        else l=mid+1;
    }
    ans--;
    vector<int>kq;
    multiset<ii>s;
    l=1;
    for(int i=1;i<=n;i++)
    {
        while(true)
        {
            if(i==l||a[i].x-a[l].x<=ans)break;
            s.erase(s.find(mp(a[l].y,l)));
            l++;
        }
        auto L=s.lower_bound(mp(a[i].y-ans,-1));
        auto R=s.upper_bound(mp(a[i].y+ans,n+1));
        while(L!=R)
        {
            int id=L->se;
            kq.push_back(max(a[i].x-a[id].x,abs(a[i].y-a[id].y)));
            L++;
        }
        s.insert(mp(a[i].y,i));
    }
    while(kq.size()<k)kq.push_back(ans+1);
    sort(kq.begin(),kq.end());
    for(int x:kq)cout<<x<<'\n';
}
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if(fopen(task".inp","r"))
    {
        freopen(task".inp","r",stdin);
        freopen(task".out","w",stdout);
    }
    init();
    process();
    cerr <<endl<< "TIME : " << clock() * 0.001 << "s" << endl ;
}

Compilation message (stderr)

road_construction.cpp: In function 'int main()':
road_construction.cpp:144:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  144 |         freopen(task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
road_construction.cpp:145:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  145 |         freopen(task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 6 / 6
• Subtask 3: 7 / 7
• Subtask 4: 20 / 20
• Subtask 5: 27 / 27
• Subtask 6: 35 / 35