Submission #245470

#	Time	Username	Problem	Language	Result	Execution time	Memory
245470		LittleFlowers__	The Big Prize (IOI17_prize)	C++17	20 / 100	92 ms	6032 KiB

prize

#include <bits/stdc++.h>
using namespace std;
#define in ({int x=0;int c=getchar(),n=0;for(;!isdigit(c);c=getchar()) n=(c=='-');for(;isdigit(c);c=getchar()) x=x*10+c-'0';n?-x:x;})
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int l,int r){return l+rng()%(r-l+1);}
#define fasty ios_base::sync_with_stdio(0),cin.tie(0);
#define forinc(a,b,c) for(int a=b,_c=c;a<=_c;++a)
#define fordec(a,b,c) for(int a=b,_c=c;a>=_c;--a)
#define forv(a,b) for(auto&a:b)
#define fi first
#define se second
#define pb push_back
#define ii pair<int,int>
#define mt make_tuple
#define all(a) a.begin(),a.end()
#define reset(f, x) memset(f, x, sizeof(f))
#define gg exit(0);

#include "prize.h"

const int N=200010;

int asked[N];
vector<int> f[N];


vector<int> qry(int i){
    if(asked[i]) return f[i];
    asked[i]=1;
    return f[i]=ask(i-1);
}

int small=-1;

int same(int i,int j){
    auto x=qry(j);
    return x[0]+x[1]==small;
}
int cnt(int i,int j){
    if(i>j)  swap(i,j);
    auto x=qry(i), y=qry(j);
    return y[0]-x[0]-(x[0]+x[1]>y[0]+y[1]);
}

int find_best(int n){
    int l=1,tmp=-1;
    int shu=1;
    forinc(t,1,200){
        //int j=t>1 ? rnd(1,n) : 1;
        int j;
        if(t==1) j=1; else{
            int g=rng();
            g*=shu;
            j=(g%n+n)%n+1;

        }
        auto a=qry(j);
        if(a[0]+a[1]==0) return j-1;
        if(tmp<a[0]+a[1]) tmp=a[0]+a[1];
        shu=a[0]+a[1];
    }

    forinc(j,1,500){
        auto a=qry(j);
        if(a[0]+a[1]==0) return j-1;
        if(small<a[0]+a[1]) small=a[0]+a[1];
    }

    if(small>tmp) exit(-1);

    small=tmp;
    int i=l, sz=0;
    vector<int> val;
    vector<int> lf(555),rt(555);
    forinc(i,0,500){
        lf[i]=1;
        rt[i]=n;
    }
    int cur=0;
    while(i<n){
        int le=max(i+1,lf[cur]),mi,ri=rt[cur]; cur++;
        while(le<=ri){
            mi=(le+ri)/2;
            if(same(l,mi)){
                forinc(j,cnt(l,mi),500)   lf[j]=max(lf[j],mi);
                forinc(j,cur,cnt(l,mi)-1) rt[j]=min(rt[j],mi);
            }
            if(same(l,mi) && cnt(l,mi)==sz) i=mi,le=mi+1; else ri=mi-1;
        }
        if(i==n) break;
        auto a=qry(++i);
        if(a[0]+a[1]==0) return i-1;
        sz++;
    }
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:95:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

• Subtask 1: 20 / 20
• Subtask 2: 0 / 80