Submission #45051

#	Time	Username	Problem	Language	Result	Execution time	Memory
45051		Mamnoon_Siam	Gap (APIO16_gap)	C++17	30 / 100	94 ms	3568 KiB

gap

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

int n;

typedef long long ll;

void MinMax(ll, ll, ll*, ll*);

ll ceil(ll x, ll d) {
	return (x - 1) / d + 1;
}

ll solve_naive() {
	ll l = 0, r = 1000000000000000000LL;
	vector<ll> v;
	int lim = (n + 1) / 2;
	for(int i=1; i<=lim; i++) {
		ll x, y;
		MinMax(l, r, &x, &y);
		v.push_back(x);
		if(x != y) v.push_back(y);
		l = x + 1;
		r = y - 1;
	}
	sort(v.begin(), v.end());
	ll ret = 0;
	for(int i=1; i<(ll)v.size(); i++) {
		ret = max(ret, v[i] - v[i-1]);
	} return ret;
}

ll solve_proway() {
	ll L = 0, R = 1e18;
	MinMax(L, R, &L, &R);
	if(n == 2) return R - L;
	ll big = ceil(R - L - 1, (ll)n-2);
	ll small = (R - L - 1) / (n - 2);
	ll big_cnt = (R - L - 1) % (n-2);
	ll small_cnt = (n - 2) - big_cnt;
	vector<pair<ll, ll>> v;
	ll nxt = L;
	for(ll i=1, l = L+1; i<=big_cnt; i++, l += big) {
		ll r = l + big - 1;
		ll x, y;
		MinMax(l, r, &x, &y);
		if(x != -1) {
			v.push_back(make_pair(x, y));
		} nxt = r+1;
	}
	for(ll i = 1, l = nxt; i <= small_cnt; i++, l += small) {
		ll r = l + small - 1;
		ll x, y;
		MinMax(l, r, &x, &y);
		if(x != -1) {
			v.push_back(make_pair(x, y));
		}
	}
	int tot = 2;
	for(pair<ll, ll> b : v) {
		if(b.first == b.second) tot++;
		else tot += 2;
	}
	if(tot == n) {
		ll ret = 0;
		ret = max(ret, v[0].first - L);
		ret = max(ret, R - v.back().second);
		for(int i=0; i<v.size(); i++) {
			ret = max(ret, v[i].second - v[i].first);
		}
		for(int i=1; i<v.size(); i++) {
			ret = max(ret, v[i].first - v[i-1].second);
		}
		return ret;
	}
	else {
		ll ret = 0;
		ret = max(ret, v[0].first - L);
		ret = max(ret, R - v.back().second);
		for(int i=0; i<v.size(); i++) {
			ret = max(ret, v[i].first - v[i-1].second);
		} return ret;
	}
}

long long findGap(int32_t T, int32_t N)
{
	n = N;
	if(T == 1) return solve_naive();
	else return solve_proway();
	return 0;
}

Compilation message (stderr)

gap.cpp: In function 'll solve_proway()':
gap.cpp:68:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0; i<v.size(); i++) {
                ~^~~~~~~~~
gap.cpp:71:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=1; i<v.size(); i++) {
                ~^~~~~~~~~
gap.cpp:80:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0; i<v.size(); i++) {
                ~^~~~~~~~~

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