Submission #51167

#	Time	Username	Problem	Language	Result	Execution time	Memory
51167		aome	Wiring (IOI17_wiring)	C++17	100 / 100	124 ms	15520 KiB

wiring

#include <bits/stdc++.h>
#include "wiring.h"

using namespace std;

const long long INF = 1e18;
	
vector< vector<int> > group;
vector< vector<long long> > sum, dp;
vector< pair<int, int> > vec;

void upd(long long &x, long long y) { x = min(x, y); }

inline long long get(int id, int l, int r) {
	return sum[id][r] - sum[id][l - 1];
}

long long min_total_length(vector<int> r, vector<int> b) {
	for (auto i : r) vec.push_back({i, 0});
	for (auto i : b) vec.push_back({i, 1});

	sort(vec.begin(), vec.end());
	for (int i = 0; i < vec.size(); ++i) {
		int j = i;
		int id = group.size();

		group.push_back(vector<int>());
		sum.push_back(vector<long long>());
		dp.push_back(vector<long long>());

		while (j < vec.size() && vec[j].second == vec[i].second) {
			group[id].push_back(vec[j++].first);
		}

		sum[id].assign(j - i + 1, 0);
		dp[id].assign(j - i + 1, INF);

		for (int k = 1; k <= j - i; ++k) {
			sum[id][k] = sum[id][k - 1] + group[id][k - 1];
		}

		i = j - 1;
	}

	dp[0][0] = 0;
	int n = group.size();
	for (int i = 0; i < n; ++i) {
		int sz = group[i].size();

		for (int j = 0; j < sz; ++j) {
			if (i) {
				upd(dp[i][j + 1], dp[i][j] + group[i][j] - group[i - 1].back());
			}
			if (i != n - 1) {
				upd(dp[i][j + 1], dp[i][j] + group[i + 1][0] - group[i][j]);
				if (sz - j <= group[i + 1].size()) {
					upd(dp[i + 1][sz - j], dp[i][j] + get(i + 1, 1, sz - j) - get(i, j + 1, sz));
				}
			}
		}

		if (i != n - 1) {
			upd(dp[i + 1][0], dp[i][sz]);
		}
		else return dp[i][sz];
	}
}

Compilation message (stderr)

wiring.cpp: In function 'long long int min_total_length(std::vector<int>, std::vector<int>)':
wiring.cpp:23:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < vec.size(); ++i) {
                  ~~^~~~~~~~~~~~
wiring.cpp:31:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while (j < vec.size() && vec[j].second == vec[i].second) {
          ~~^~~~~~~~~~~~
wiring.cpp:56:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (sz - j <= group[i + 1].size()) {
         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
wiring.cpp:67:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

• Subtask 1: 7 / 7
• Subtask 2: 13 / 13
• Subtask 3: 10 / 10
• Subtask 4: 25 / 25
• Subtask 5: 45 / 45