Submission #82181

#	Time	Username	Problem	Language	Result	Execution time	Memory
82181		SecretAgent007	The Big Prize (IOI17_prize)	C++17	100 / 100	47 ms	5456 KiB

prize

#include <bits/stdc++.h>
#include "prize.h"
using namespace std;

const int N = 200010;
const int S = 1000;
vector<int> memo[N];
inline vector<int> &query(int i) {
    if (memo[i].empty())
        memo[i] = ask(i);
    return memo[i];
}
inline int querysum(int i) {
    vector<int> &ret = query(i);
    return ret[0]+ret[1];
}

int mx = 0, ans = -1;
void solve(int l, int r, int k, int dl, int dr)
{
    if (l > r) return;
    if (k == 0) return;
    int start = l, rem = dl, cnt = 0;
    for (int i = 1; i <= k; ++i) {
        if (ans != -1) break;
        int p = (l-1)+max(1, (r-l+2)/(k+1))*i;
        if (p >= l && p <= r) {
            if (querysum(p) == 0) { ans = p; break; }
            if (querysum(p) != mx) { ++cnt; continue; }
            int val = query(p)[0];
            solve(start, p-1, val-rem, rem, query(p)[1]);
            start = p+1;
            rem = val;
        }
    }
    if (start <= r && ans == -1 && cnt < k)
        solve(start, r, k-(rem-dl), rem, dr);
}

int find_best(int n)
{
    for (int i = 1; i < S; ++i) {
        int p = max(1, n/S)*i;
        if (p >= 0 && p < n) {
            if (querysum(p) == 0)
                return p;
            mx = max(mx, querysum(p));
        }
    }
    int start = 0, rem = 0;
    for (int i = 1; i < S; ++i) {
        int p = max(1, n/S)*i;
        if (p >= 0 && p < n && querysum(p) == mx) { //querysum already computed
            int val = query(p)[0]; //val equals the total number of higher gift than lollipop on the left
            solve(start, p-1, val-rem, rem, query(p)[1]);
            if (ans != -1) return ans;
            start = p+1;
            rem = val;
        }
    }
    if (start <= n-1)
        solve(start, n-1,mx-rem, rem, 0);

	return ans;
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:61:5: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
     if (start <= n-1)
     ^~
prize.cpp:64:2: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  return ans;
  ^~~~~~

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