Submission #501456

#	Time	Username	Problem	Language	Result	Execution time	Memory
501456		Stickfish	Gap (APIO16_gap)	C++17	30 / 100	47 ms	2644 KiB

gap

#include "gap.h"
#include <vector>
#include <algorithm>
using ll = long long;
using namespace std;

const ll INF = 1.77013e18;

ll find_recur(ll mn, ll mx) {
    if (mx - mn == 1) {
        return 1;
    }
    if (mx - mn == 2) {
        ll nmn, nmx;
        MinMax(mn + 1, mx - 1, &nmn, &nmx);
        if (nmn == -1)
            return 2;
        return 1;
    } 
    ll md = (mn + mx) / 2;
    ll lmn, lmx;
    MinMax(mn + 1, md, &lmn, &lmx);
    ll rmn, rmx;
    MinMax(md + 1, mx - 1, &rmn, &rmx);
    if (lmn == -1 && rmn == -1) {
        return mx - mn;
    }
    if (lmn == -1) {
        return rmn - mn;
    }
    if (rmn == -1) {
        return mx - lmx;
    }
    return max(find_recur(lmn, lmx), find_recur(rmn, rmx));
}

ll findGap(int T, int N) {
    if (T == 1) {
        vector<ll> mn;
        vector<ll> mx;
        while (mn.size() + mx.size() < N) {
            ll nmn, nmx;
            if (mn.empty()) {
                MinMax(1ll, INF, &nmn, &nmx);
            } else {
                MinMax(mn.back() + 1, mx.back() - 1, &nmn, &nmx);
            }
            mn.push_back(nmn);
            if (nmn != nmx)
                mx.push_back(nmx);
        }
        reverse(mx.begin(), mx.end());
        for (auto x : mx) {
            mn.push_back(x);
        }
        ll ans = 0;
        for (int i = 0; i + 1 < N; ++i) {
             ans = max(ans, mn[i + 1] - mn[i]);
        }
        return ans;
    } else {
        ll mn, mx;
        MinMax(1ll, INF, &mn, &mx);
        return find_recur(mn, mx);
    }
    return 0;
}

Compilation message (stderr)

gap.cpp: In function 'll findGap(int, int)':
gap.cpp:41:38: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   41 |         while (mn.size() + mx.size() < N) {
      |                ~~~~~~~~~~~~~~~~~~~~~~^~~

• Subtask 1: 30 / 30
• Subtask 2: 0 / 70