Submission #470651

#	Time	Username	Problem	Language	Result	Execution time	Memory
470651		Carmel_Ab1	The Big Prize (IOI17_prize)	C++17	20 / 100	122 ms	328 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
typedef vector<int>vi;
typedef pair<int,int>pi;
typedef vector<pi> vpi;
#define pb push_back
#define all(x) x.begin(),x.end()
//#include "grader.cpp"

int find_best(int n) {

    int sz=450;
    vi prv={-1,-1};
    vpi segs;
    for(int i=0; i<n; i+=sz){
        vi s=(prv[0]==-1?ask(i):prv),e=ask(min(n-1,i+sz));
        if(s[0]==0 && s[1]==0)
            return i;
        if(e[0]==0 && e[1]==0)
            return min(i+sz,n-1);
        if(e[0]==s[0])
            continue;
        segs.pb({i,min(i+sz,n-1)});
        prv=e;
    }
    srand(time(0));
    random_shuffle(all(segs));
    
    vector<bool>vis(2e5);
    for(pi p:segs){
        int l=p.first,r=p.second;
        for(int i=l+1; i<r; i++){
            if(vis[i])
                continue;
            vi v=ask(i);
            if(v==vi(2,0))
                return i;
            for(int j=i; j<vis.size() && !vis[j] && v[1]==0; j++)
                vis[j]=1;
            for(int j=i;0<=j && !vis[j] && v[0]==0; j--)
                vis[j]=1;
        }
    }
    assert(0);
    return -1;
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:39:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<bool>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |             for(int j=i; j<vis.size() && !vis[j] && v[1]==0; j++)
      |                          ~^~~~~~~~~~~

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