제출 #111453

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
111453		ecasdqina	Fireworks (APIO16_fireworks)	C++14	7 / 100	10 ms	428 KiB

fireworks

#include <bits/stdc++.h>
using namespace std::literals::string_literals;
using i64 = long long;
using std::cout;
using std::endl;
using std::cin;

template<typename T>
std::vector<T> make_v(size_t a){return std::vector<T>(a);}

template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts){
  return std::vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}

int main() {
	int n, m; scanf("%d%d", &n, &m);
	std::vector<int> leaf(m);
	std::vector<std::vector<std::pair<int, i64>>> g(n + m); n += m;
	for(int i = 1; i < n; i++) {
		int a; i64 b; scanf("%d%lld", &a, &b);
		
	//	g[i].push_back({a - 1, b});
		g[a - 1].push_back({i, b});
	}
	
	std::vector<i64> dist(n, 0);
	std::function<void (int, int, i64)> dfs = [&](int v, int par, i64 ari) {
		dist[v] = ari;
		for(auto e: g[v]) {
			if(e.first == par) continue;
			dfs(e.first, v, ari + e.second);
		}
	};
	dfs(0, -1, 0);
	
	std::function<i64 (std::vector<i64>&)> OSNIKTR = [](std::vector<i64>& vec) {
		i64 X = 0, Y = 1LL << 60;
		std::vector<i64> s(vec.size() + 1, 0);
		for(int i = 0; i < vec.size(); i++) s[i + 1] = s[i] + vec[i];
		
		for(i64 i = 0; i < vec.size(); i++) {
			i64 tmp = std::abs(vec[i]);
			tmp += i * vec[i] - s[i];
			tmp += (s.back() - s[i]) - ((i64)vec.size() - i) * vec[i];
			if(tmp < Y) {
				Y = tmp;
				X = vec[i];
			}
		}
		
		return X;
	};
	
	i64 tmp = 0;
	std::function<i64 (int, int, i64)> solve = [&](int v, int par, i64 t) {
		if(v > n - m - 1) return t - (i64)dist[v];
		
		std::vector<i64> vec;
		for(auto e: g[v]) {
			if(e.first == par) continue;
			vec.push_back(solve(e.first, v, t));
		}
		sort(begin(vec), end(vec));
		
		if(v == 0) {
			for(auto v: vec) tmp += std::abs(v);
			return 0LL;
		}
		
		i64 makino = OSNIKTR(vec);
		for(auto v: vec) tmp += std::abs(v - makino);
		return makino;
	};
		
	
	i64 ans = 1LL << 60;
	i64 ok = 0, ng = 1e15;
	for(int loop = 0; loop < 100; loop++) {
		i64 ml = (ok + ok + ng) / 3LL;
		i64 mr = (ok + ng + ng) / 3LL;
		
		tmp = 0;
		solve(0, -1, ml);
		i64 L = tmp; tmp = 0;
		solve(0, -1, mr);
		i64 R = tmp;
		
		ans = std::min({ans, L, R});
		if(L < R) ng = mr;
		else ok = ml;
	}
	for(i64 i = ok - 1000; i < ok + 1000; i++) {
		tmp = 0;
		solve(0, -1, i);
		ans = std::min(ans, tmp);
	}
	
	printf("%lld\n", ans);
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

fireworks.cpp: In lambda function:
fireworks.cpp:40:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i < vec.size(); i++) s[i + 1] = s[i] + vec[i];
                  ~~^~~~~~~~~~~~
fireworks.cpp:42:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(i64 i = 0; i < vec.size(); i++) {
                  ~~^~~~~~~~~~~~
fireworks.cpp: In function 'int main()':
fireworks.cpp:17:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  int n, m; scanf("%d%d", &n, &m);
            ~~~~~^~~~~~~~~~~~~~~~
fireworks.cpp:21:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int a; i64 b; scanf("%d%lld", &a, &b);
                 ~~~~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 0 / 19
• Subtask 3: 0 / 29
• Subtask 4: 0 / 45