Submission #253178

#	Time	Username	Problem	Language	Result	Execution time	Memory
253178		14kg	Palembang Bridges (APIO15_bridge)	C++11	100 / 100	85 ms	7056 KiB

bridge

#include <stdio.h>
#include <algorithm>
#include <queue>
#include <vector>
#include <functional>
#define N 100002
#define INF 999999999999999999
#define min2(x,y) (x<y?x:y)
 
using namespace std;
int n, K;
long long dp1[N], dp2[N];
pair<int, int> in[N];
priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > > Q1;
priority_queue<pair<int, int> > Q2;
 
bool cmp(pair<int, int> x, pair<int, int> y) {
	return x.first + x.second < y.first + y.second;
}
int main() {
	//freopen("input.txt", "r", stdin);
	int k, x, y;
	char in_a, in_b;
	long long R = 0;
 
	scanf("%d %d ", &K, &k);
	while (k--) {
		scanf("%c %d %c %d ", &in_a, &x, &in_b, &y);
		if (x > y) x += y, y = x - y, x -= y;
		R += (long long)(y - x);
		if (in_a != in_b) R++, in[++n] = { x,y };
	} sort(in + 1, in + n + 1, cmp);
 
	k = 0, x = 0, y = 0;
	for (int i = 1; i <= n; i++) {
		dp1[i] = dp1[i - 1];
 
		if (k < in[i].first) {
			y++, dp1[i] += (long long)(in[i].first - k);
			Q1.push({ in[i].first,1 }), Q1.push({ in[i].second,2 });
		}
		else if (in[i].second < k) 
			x++, dp1[i] += (long long)(k - in[i].second);
		else Q1.push({ in[i].second,2 });
 
		while (Q1.empty() == false && x < y) {
			dp1[i] += (long long)(Q1.top().first - k)*(long long)(x - y);
			if (Q1.top().second == 1) y--;
			else x++;
			k = Q1.top().first, Q1.pop();
		}
	}
 
	k = in[n].second, x = 0, y = 0;
	for (int i = n; i >= 1; i--) {
		dp2[i] = dp2[i + 1];
 
		if (in[i].second < k) {
			x++, dp2[i] += (long long)(k - in[i].second);
			Q2.push({ in[i].second,1 }), Q2.push({ in[i].first,2 });
		}
		else if (in[i].first > k)
			y++, dp2[i] += (long long)(in[i].first - k);
		else Q2.push({ in[i].first,2 });
 
		while (Q2.empty() == false && x > y) {
			dp2[i] += (long long)(k - Q2.top().first)*(long long)(y - x);
			if (Q2.top().second == 1) x--;
			else y++;
			k = Q2.top().first, Q2.pop();
		}
	}
	
	if (K == 1) printf("%lld", R + dp1[n] * 2);
	else {
		long long MIN = INF;
		for (int i = 0; i <= n; i++) MIN = min2(MIN, dp1[i] + dp2[i + 1]);
		printf("%lld", R + MIN * 2);
	}
}

Compilation message (stderr)

bridge.cpp: In function 'int main()':
bridge.cpp:26:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d ", &K, &k);
  ~~~~~^~~~~~~~~~~~~~~~~~
bridge.cpp:28:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%c %d %c %d ", &in_a, &x, &in_b, &y);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 14 / 14
• Subtask 3: 9 / 9
• Subtask 4: 32 / 32
• Subtask 5: 37 / 37