Submission #728105

#	Time	Username	Problem	Language	Result	Execution time	Memory
728105		nguyentunglam	The Big Prize (IOI17_prize)	C++17	0 / 100	106 ms	5316 KiB

prize

#include<bits/stdc++.h>
using namespace std;
#include "prize.h"
mt19937 rng(172831923);
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int l, int r) {
    return l + rng() % (r - l + 1);
}

const int N = 2e5 + 10;
vector<int> ans[N];
int worst;
int check(int i, int j) {
    if (ans[j].empty()) ans[j] = ask(j);
    if (ans[0][j] + ans[1][j] != worst) return 2;
    int tmp = ans[0][j] + ans[1][j] + ans[0][i] + ans[1][i] - worst;
    return tmp > 0;
}

int find_best(int n) {

    vector<tuple<int, int, int> > block;
    int T = max(1, n / 785);
    for(int i = 0; i < n; i += T) {
        ans[i] = ask(i);
        worst = max(worst, ans[i][0] + ans[i][1]);
    }

    for(int i = 1; i < n; i++) if (i % T) {
        if (ans[i].empty()) ans[i] = ask(i);
        if (ans[i][0] + ans[i][1] != worst) continue;
        int l = i, r = n;
        for(int j = T; j < n; j++) if (j > i) {
            if (check(i, j)) {
                r = j;
                break;
            }
            l = j;
        }

        int last = l;
        while (l <= r) {
            int mid = l + r >> 1;
            int tmp = check(i, mid);
            if (!tmp) {
                last = mid;
                l = mid + 1;
            }
            else r = mid - 1;
        }
        i = last;
    }

    for(int i = 0; i < n; i++) if (!ans[i].empty() && ans[i][0] + ans[i][1] == 0) {
        return i;
    }
    return 0;
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:43:25: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   43 |             int mid = l + r >> 1;
      |                       ~~^~~

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