제출 #211029

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
211029		Kevin_Zhang_TW	Job Scheduling (IOI19_job)	C++17	19 / 100	142 ms	29480 KiB

job

#include "job.h"
#include <bits/extc++.h>
#include <vector>
#define pb emplace_back
const int maxn = 200010;
using ll = long long;
using namespace std;
int deg[maxn], togo[maxn], tl, n;
ll res;
vector<int> edge[maxn], sorted[maxn];
ll p[maxn], u[maxn], d[maxn];
struct cmp {
	bool operator()(int a, int b) const {
		return d[a] * u[b] > d[b] * u[a];
	}
};
void sub_merge(int a, int b) {
	res -= (ll)d[b] * u[a];
	d[a] += d[b];
	u[a] += u[b];
}
void get_ans() {
	res = 0;
	for (int i = 0;i < n;++i) {
		int now = togo[i];
		assert(now || i == n-1);
		for (int u : edge[now]) {
			if (sorted[u].size() > sorted[now].size()) swap(sorted[u], sorted[now]);
			//int a = sorted[now].size();
			for (int s : sorted[u]) sorted[now].pb(s);
			//sorted[now].insert(sorted[now].end(), sorted[u].begin(), sorted[u].end());
			//inplace_merge(sorted[now].begin(), sorted[now].begin()+a, sorted[now].end(), cmp());
		}
		//sort(sorted[now].begin(), sorted[now].end(), cmp());
//		while (sorted[now].size() && cmp()(now, sorted[now].back())) {
//			sub_merge(now, sorted[now].back());
//			sorted[now].pop_back();
//		}
//		sorted[now].pb(now);
		if (now)
			sorted[now].pb(now);
	}
	auto &v = sorted[0];
	sort(v.begin(), v.end(), cmp());
	ll t = 0;
	auto dojob = [&](int a) {
		//cerr << "dojob " << a << ' ' << "d, u : " << d[a] << ' ' << u[a] << '\n';
		t += d[a];
		res += t * u[a];
	};
	dojob(0);
	while (v.size()) {
		dojob(v.back());
		v.pop_back();
	}
}
long long bf() {
	static bool did[maxn];
	auto &v = edge[0];
	sort(v.begin(), v.end(), cmp());
	for (int u : v)assert(u);
	ll t = 0;
	ll res = 0;
	auto dojob = [&](int a) {
		t += d[a];
		res += t * u[a];
	};
	dojob(0);
	for (int i = (int)v.size()-1;i >= 0;--i)
		dojob(v[i]);
	return res;
}
long long scheduling_cost(std::vector<int> p, std::vector<int> u, std::vector<int> d) {
	n = p.size();
	for (int i = 1;i < n;++i) edge[p[i]].pb(i);
	for (int i = 1;i < n;++i) ++deg[ p[i] ];
	for (int i = 0;i < n;++i) if (deg[i] == 0)
		togo[tl++] = i;
	for (int i = 0;i < n;++i) {
		int now = togo[i];
		if (now == 0) {
			assert(n-1 == i);
		   	break;
		}
		if ( --deg[ p[now] ] == 0) togo[tl++] = p[now];
	}
	for (int i = 0;i < n;++i) 
		::p[i] = p[i], ::u[i] = u[i], ::d[i] = d[i];
	get_ans();
	return res;
	//cerr << "my ans is : " << res << '\n';
	//res = 0;
	//cerr << "brute force : " << bf() << '\n';
	return bf();
}

컴파일 시 표준 에러 (stderr) 메시지

job.cpp: In function 'long long int bf()':
job.cpp:58:14: warning: unused variable 'did' [-Wunused-variable]
  static bool did[maxn];
              ^~~
job.cpp: At global scope:
job.cpp:58:14: warning: 'did' defined but not used [-Wunused-variable]

• Subtask 1: 0 / 5
• Subtask 2: 7 / 7
• Subtask 3: 12 / 12
• Subtask 4: 0 / 18
• Subtask 5: 0 / 21
• Subtask 6: 0 / 37