Submission #970666

#	Time	Username	Problem	Language	Result	Execution time	Memory
970666		yeediot	Divide and conquer (IZhO14_divide)	C++17	100 / 100	60 ms	17344 KiB

divide

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
#define ykh mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count())
#define __lg(x) 63-__builtin_clzll(x)
#define pow2(x) (1LL<<x)
void __print(int x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef local
void setio(){freopen("/Users/iantsai/Library/Mobile Documents/com~apple~CloudDocs/cpp/Empty.md","r",stdin);}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
void setio(){}
#define debug(x...)
#endif
void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
struct line{
    int a,b;
    int operator()(const int x)const{
        return a*x+b;
    }
};
bool check(line l1,line l2,line l3){
    return (l3.b-l2.b)*(l1.a-l2.a)<=(l2.b-l1.b)*(l2.a-l3.a);
}
struct node{
    int x,g,d;
    bool operator < (const node b)const{
        return x<b.x;
    }
};
const int mxn=2e5+5;
vector<node>v;
int pre[mxn];
int preg[mxn];
vector<int>temp;
int n;
struct segtree{
    int seg[4*mxn];
    int getid(int x){
        return lower_bound(all(temp),x)-temp.begin()+1;
    }
    void build(int l=1,int r=2*n,int id=1){
        seg[id]=-8e18;
        if(l==r){
            return ;
        }
        int mm=l+r>>1;
        build(l,mm,id*2);
        build(mm+1,r,id*2+1);
    }
    void modify(int l,int r,int id,int p,int v){
        if(l==r){
            seg[id]=max(seg[id],v);
            return ;
        }
        int mm=l+r>>1;
        if(p<=mm){
            modify(l,mm,id*2,p,v);
        }
        else{
            modify(mm+1,r,id*2+1,p,v);
        }
        seg[id]=max(seg[id*2],seg[id*2+1]);
    }
    void modify(int p,int v){
        modify(1,2*n,1,p,v);
    }
    int query(int l,int r,int id,int ql,int qr){
        if(qr<l or r<ql){
            return -8e18;
        }
        if(ql<=l and r<=qr){
            return seg[id];
        }
        int mm=l+r>>1;
        return max(query(l,mm,id*2,ql,qr),query(mm+1,r,id*2+1,ql,qr));
    }
    int query(int ql,int qr){
        return query(1,2*n,1,ql,qr);
    }
}tr;
signed main(){
    setio();
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    cin>>n;
    v.pb({-1,0,0});
    for(int i=0;i<n;i++){
        int x,g,d;
        cin>>x>>g>>d;
        v.pb({x,g,d});
    }
    sort(all(v));
    for(int i=1;i<=n;i++){
        pre[i]=pre[i-1]+v[i].d;
        preg[i]=preg[i-1]+v[i].g;
        temp.pb(pre[i]-v[i].x);
        temp.pb({pre[i-1]-v[i].x});
    }
    sort(all(temp));
    temp.resize(unique(all(temp))-temp.begin());
    tr.build();
    int ans=0;
    for(int i=1;i<=n;i++){
        tr.modify(tr.getid(pre[i-1]-v[i].x),-preg[i-1]);
        chmax(ans,preg[i]+tr.query(1,tr.getid(pre[i]-v[i].x)));
        debug(ans);
    }
    cout<<ans<<'\n';
}
 /*
 input:
 pree[r]-pree[l-1]>=x[r]-x[l]
 pree[r]-x[r]>=pree[l-1]-x[l]
 */















 

Compilation message (stderr)

divide.cpp: In member function 'void segtree::build(long long int, long long int, long long int)':
divide.cpp:76:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   76 |         int mm=l+r>>1;
      |                ~^~
divide.cpp: In member function 'void segtree::modify(long long int, long long int, long long int, long long int, long long int)':
divide.cpp:85:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   85 |         int mm=l+r>>1;
      |                ~^~
divide.cpp: In member function 'long long int segtree::query(long long int, long long int, long long int, long long int, long long int)':
divide.cpp:104:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  104 |         int mm=l+r>>1;
      |                ~^~
divide.cpp: In function 'void setIO(std::string)':
divide.cpp:42:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
divide.cpp:43:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 17 / 17
• Subtask 2: 31 / 31
• Subtask 3: 52 / 52