| # | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
|---|---|---|---|---|---|---|---|
| 788994 | Alcabel | Aliens (IOI16_aliens) | C++17 | 0 ms | 0 KiB |
이 제출은 이전 버전의 oj.uz에서 채점하였습니다. 현재는 제출 당시와는 다른 서버에서 채점을 하기 때문에, 다시 제출하면 결과가 달라질 수도 있습니다.
#include <bits/stdc++.h>
#ifndef LOCAL
#include "aliens.h"
#endif
using namespace std;
const long long inf = 1e13;
const int maxiters = 200;
struct Line {
int a;
long double b;
Line() {}
Line(int _a, long double _b) {
a = _a, b = _b;
}
long double f(int x) {
return a * 1ll * x + b;
}
~Line() {}
};
const long double eps = 1e-4;
int sign(long double x) {
if (x > eps) { return 1; }
if (x < eps) { return -1; }
return 0;
}
long long intersect(const Line& A, const Line& B) {
// x = (B.b - A.b) / (A.a - B.a)
long double numer = B.b - A.b, denom = A.a - B.a;
return ceill(numer / denom);
/*int sn = sign(numer), sd = sign(denom);
numer *= sn, denom *= sd;
if (sn * sd < eps) {
return numer / denom * -1;
}
return (numer + denom - 1) / denom;*/
}
long long take_photos(int n, int m, int k, vector<int> rows, vector<int> cols) {
vector<int> maxRight(m, -1);
for (int i = 0; i < n; ++i) {
int l = min(rows[i], cols[i]);
int r = max(rows[i], cols[i]);
maxRight[l] = max(maxRight[l], r + 1);
}
vector<pair<int, int>> segs;
for (int l = 0; l < m; ++l) {
if (maxRight[l] != -1 && (segs.empty() || segs.back().second < maxRight[l])) {
segs.emplace_back(l, maxRight[l]);
}
}
n = segs.size();
k = min(k, n);
vector<pair<long double, int>> dp(n);
vector<Line> lines;
vector<long double> optX;
vector<int> cntSegs;
long double left = -inf, right = inf;
long long ans = (segs.back().second - segs[0].first) * 1ll * (segs.back().second - segs[0].first);
for (int iter = 0; iter < maxiters; ++iter) {
long double mid = left + (right - left) / 2;
lines = {};
optX = {};
cntSegs = {};
dp[0] = {(segs[0].second - segs[0].first) * 1ll * (segs[0].second - segs[0].first) + mid, 1};
for (int i = 1, ptr = 0; i < n; ++i) {
// cerr << "i: " << i << '\n';
int lenInter = max(0, segs[i - 1].second - segs[i].first);
Line l(-2 * segs[i].first, dp[i - 1].first - lenInter * 1ll * lenInter + segs[i].first * 1ll * segs[i].first);
while (!lines.empty() && sign(intersect(lines.back(), l) - optX.back()) != 1) {
optX.pop_back();
lines.pop_back();
cntSegs.pop_back();
}
if (!lines.empty()) {
optX.emplace_back(intersect(lines.back(), l));
} else {
optX.emplace_back(-1);
}
lines.emplace_back(l);
cntSegs.emplace_back(dp[i - 1].second);
// cerr << "inserted!\n";
ptr = min(ptr, (int)lines.size() - 1);
while (ptr + 1 < (int)lines.size() && optX[ptr + 1] <= segs[i].second) {
++ptr;
}
// cerr << "found!\n";
dp[i] = {lines[ptr].f(segs[i].second) + segs[i].second * 1ll * segs[i].second + mid, cntSegs[ptr] + 1};
if (sign((segs[i].second - segs[0].first) * 1ll * (segs[i].second - segs[0].first) + mid - dp[i].first) != 1) {
dp[i] = {(segs[i].second - segs[0].first) * 1ll * (segs[i].second - segs[0].first) + mid, 1};
}
}
if (dp[n - 1].second <= k) {
right = mid;
long long cur = floorl(dp.back().first - dp.back().second * mid);
if (sign(dp.back().first - dp.back().second * mid - cur) == 1) {
++cur;
}
ans = min(ans, cur);
} else {
left = mid;
}
/*cerr << "g: " << g << ", subtracted:\n";
for (int i = g - 1; i < n; ++i) {
cerr << dp[layer ^ 1][i] - dp[layer][i] << ' ';
}
cerr << '\n';
ans = min(ans, dp[layer][n - 1]);*/
}
return ans;
}
void solve() {
int n, m, k;
cin >> n >> m >> k;
vector<int> r(n), c(n);
for (int i = 0; i < n; ++i) {
cin >> r[i] >> c[i];
}
cout << take_photos(n, m, k, r, c) << '\n';
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
int T = 1;
cin >> T;
while (T--) {
solve();
cerr << "-----------\n";
cout << "-----------\n";
}
#else
int T = 1;
cin >> T;
while (T--) {
solve();
}
#endif
return 0;
}