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Submission #112185

# Submission time Handle Problem Language Result Execution time Memory
112185 2019-05-17T18:26:38 Z someone_aa The Big Prize (IOI17_prize) C++17
20 / 100
 66 ms 600 KB 
#include "prize.h"
#include <bits/stdc++.h>

using namespace std;
const int maxn = 200100;

bool visited[maxn];

int find_best(int n) {
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

    srand(time(NULL));

    if(n <= 10000) {
        for(int i=1;i<=n;i++) {
            vector<int>v = ask(i);
            if(v[0] == v[1]) return i;
        }
    }

    int fst = 0, lst = n-1;
    for(int i=1;i<=4500;i++) {
        int x = uniform_int_distribution<int>(0, n-1)(rng);

        while(visited[x]) x = uniform_int_distribution<int>(0, n-1)(rng);

        visited[x] = true;

        vector<int>v = ask(x);

        if(v[0] == v[1] && v[0] == 0) return x;

        // looking for the last {0, 1}
        // looking for the first {1, 0}
        if(v[0] == 0) fst = max(fst, x);
        else if(v[1] == 0) lst = min(lst, x);
    }

    for(int i=fst;i<=lst;i++) {
        vector<int>v = ask(i);
        if(v[0] == v[1] && v[0] == 0) return i;
    }

	return 0;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 46 ms 504 KB Output is correct
2 Correct 25 ms 504 KB Output is correct
3 Correct 26 ms 504 KB Output is correct
4 Correct 43 ms 432 KB Output is correct
5 Correct 50 ms 504 KB Output is correct
6 Correct 30 ms 512 KB Output is correct
7 Correct 41 ms 512 KB Output is correct
8 Correct 43 ms 512 KB Output is correct
9 Correct 20 ms 504 KB Output is correct
10 Correct 23 ms 600 KB Output is correct

Subtask #2
0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 36 ms 512 KB Output is correct
2 Correct 27 ms 404 KB Output is correct
3 Correct 32 ms 508 KB Output is correct
4 Correct 40 ms 512 KB Output is correct
5 Correct 30 ms 512 KB Output is correct
6 Correct 36 ms 512 KB Output is correct
7 Correct 41 ms 512 KB Output is correct
8 Correct 26 ms 440 KB Output is correct
9 Correct 16 ms 568 KB Output is correct
10 Correct 31 ms 512 KB Output is correct
11 Incorrect 66 ms 504 KB Incorrect
12 Halted 0 ms 0 KB -