Submission #428568

#	Time	Username	Problem	Language	Result	Execution time	Memory
428568		Kevin_Zhang_TW	Aliens (IOI16_aliens)	C++17	4 / 100	1 ms	332 KiB

aliens

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pb emplace_back
#define AI(i) begin(i), end(i)
template<class T> bool chmin(T &a, T b) { return b < a && (a = b, true); }
template<class T> bool chmax(T &a, T b) { return a < b && (a = b, true); }
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() { cerr << endl; }
template<class T, class ...U> void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
template<class T> void debug(T l, T r) { while (l != r) cerr << *l << " \n"[next(l)==r], ++l; }
#else
#define DE(...) 0
#define debug(...) 0
#endif

const int MAX_N = 300010;
const ll inf = 1ll << 55;

#include "aliens.h"

ll sq(ll v) { return v * v; }

void monolize(vector<int> &r, vector<int> &c, int &n) {
	for (int i = 0;i < n;++i) {
		if (r[i] > c[i]) swap(r[i], c[i]);
	}
	vector<pair<int,int>> loc;
	for (int i = 0;i < n;++i) loc.pb(c[i], r[i]);
	sort(AI(loc));
	int sz = 0;
	for (auto [x, y] : loc) {
		while (sz) {
			auto [xx, yy] = loc[sz-1];
			if (yy < y) break;
			--sz;
		}
		loc[sz++] = {x, y};
	}
	loc.resize(sz);

	r.clear(), c.clear();
	for (auto [x, y] : loc)
		r.pb(y), c.pb(x);
	n = r.size();
}

long long take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c) {

	monolize(r, c, n);

	vector<int> allc(c); allc.pb(-1); sort(AI(allc)), allc.erase(unique(AI(allc)), end(allc));

	auto get_pos = [&](int c) -> int { 
		return lower_bound(AI(allc), c) - begin(allc);
	};

	int g = allc.size();

	vector<vector<ll>> dp(g, vector<ll>(k + 1, inf));

	fill(AI(dp[0]), 0);

	vector<vector<ll>> segmn(g, vector<ll>(g, inf));

	vector<ll> omn(g, inf);

	for (int i = 0;i < n;++i) {
		int j = get_pos(c[i]); 
		chmin(omn[j], (ll)r[i]);
	}
		
	for (int i = 0;i < g;++i) {
		segmn[i][i] = omn[i];
		for (int j = i+1;j < g;++j) 
			segmn[i][j] = min(omn[j], segmn[i][j-1]);
	}

	debug(AI(allc));

	auto cost = [&](int l, int i) {
		ll mnc = segmn[l+1][i];
		ll wid = allc[i] - mnc + 1;
		ll rep = max<ll>(0, allc[l] - mnc + 1);
		return sq(wid) - sq(rep);
	};
		
	for (int i = 1;i < g;++i) {
		for (int j = 1;j <= k;++j) {
			auto trans = [&](int l, int i) {
				return dp[l][j-1] + cost(l, i);
			};
			int l = 0, r = i-1, mid;
			while (l < r) {
				mid = l + r >> 1;
				if (trans(mid, i) < trans(mid+1, i))
					r = mid;
				else
					l = mid+1;
			}
			dp[i][j] = trans(l, i);
//			for (int l = 0;l < i;++l) {
//				chmin(dp[i][j], dp[l][j-1] + cost(l, i));
//			}
		}
	}

	debug(AI(dp[g-1]));
	return dp[g-1][k];
}

Compilation message (stderr)

aliens.cpp: In function 'long long int take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:15:20: warning: statement has no effect [-Wunused-value]
   15 | #define debug(...) 0
      |                    ^
aliens.cpp:80:2: note: in expansion of macro 'debug'
   80 |  debug(AI(allc));
      |  ^~~~~
aliens.cpp:96:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   96 |     mid = l + r >> 1;
      |           ~~^~~
aliens.cpp:15:20: warning: statement has no effect [-Wunused-value]
   15 | #define debug(...) 0
      |                    ^
aliens.cpp:109:2: note: in expansion of macro 'debug'
  109 |  debug(AI(dp[g-1]));
      |  ^~~~~

• Subtask 1: 4 / 4
• Subtask 2: 0 / 12
• Subtask 3: 0 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40