Submission #316306

#	Time	Username	Problem	Language	Result	Execution time	Memory
316306		nikatamliani	The Big Prize (IOI17_prize)	C++14	0 / 100	15 ms	9976 KiB

prize

#include <bits/stdc++.h>
using namespace std;
#include "prize.h"
vector < vector < int > > memo;
vector < int > memo_ask(int x) {
    if(!memo[x].empty()) return memo[x];
    return memo[x] = ask(x);
}
int find_best(int n) {
    if(n < 5000) {
        for(int i = 0; i < n; ++i) if(memo_ask(i)[0] + memo_ask(i)[1] == 0) return i;
    }
    int next = -1, at_most = 500;
    vector < int > bad(2); 
    memo.resize(n);
    for(int i = 0; i <= at_most; ++i) {
        if(bad[0] + bad[1] < memo_ask(i)[0] + memo_ask(i)[1]) {
            bad = memo_ask(i);
            
        }
        if(memo_ask(i)[0] == 0 && memo_ask(i)[1] == 0) return i;
    }
    map < int, int > f;
    for(int i = 0; i <= at_most; ++i) {
        ++f[memo_ask(i)[0] + memo_ask(i)[1]];
    }
    int min_sum = 1e9, count_more = 0; 
    for(auto [key, value] : f) {
        if(value >= 26) {
            min_sum = key;
            ++count_more;
            break;
        } 
    }
    assert(count_more > 1);
    const int BLOCK_SIZE = 1000;
    for(int i = at_most + 1; i < n; i = next + 1) {
        int l = i, r = n - 1; next = -1;
        vector < int > t = memo_ask(i);
        if(t[0] + t[1] < min_sum) {
            next = i;
            if(t[0] == 0 && t[1] == 0) return i; 
            continue;
        } 
        int maybe = i + BLOCK_SIZE;
        if(maybe < n && memo_ask(maybe)[0] + memo_ask(maybe)[1] >= min_sum) {
            next = maybe;
            continue;
        }
        if(maybe < n) r = maybe - 1;
        while(r >= l) {
            int m = l + r >> 1;
            if(memo_ask(m)[0] + memo_ask(m)[1]) {
                next = m;
                l = m + 1;
            } else {
                r = m - 1; 
            }
        }
    }
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:28:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   28 |     for(auto [key, value] : f) {
      |              ^
prize.cpp:52:23: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   52 |             int m = l + r >> 1;
      |                     ~~^~~
prize.cpp:14:25: warning: control reaches end of non-void function [-Wreturn-type]
   14 |     vector < int > bad(2);
      |                         ^

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