Rest Stops

#include <fstream>
#include <iostream>
#include <vector>
 
using namespace std;
 
int main() {
	ifstream in("reststops.in");
 
	int trail_len;  // no se usa
	int stop_num;
	int f_rate;
	int b_rate;
	in >> trail_len >> stop_num >> f_rate >> b_rate;
 
	vector<int> x(stop_num);  // posición de cada parada
	vector<int> c(stop_num);  // valor de sabor de cada parada
	for (int i = 0; i < stop_num; i++) { in >> x[i] >> c[i]; }
 
	// hallamos todas las paradas "mejores"
	vector<bool> good(stop_num);
	int max_tastiness = 0;
	for (int i = stop_num - 1; i >= 0; i--) {
		if (c[i] > max_tastiness) {
			// no hay paradas después de i que sean "mejores"
			good[i] = true;
			max_tastiness = c[i];
		}
	}
	int total = 0;
	for (bool i : good) total += i;
	cout << total << endl;
 
	// simulamos todo el sendero
	long long prev_stop_pos = 0;
	long long ans = 0;
	for (int i = 0; i < stop_num; i++) {
		if (good[i]) {
			long long travel_dist = x[i] - prev_stop_pos;
			long long f_time = travel_dist * f_rate;
			long long b_time = travel_dist * b_rate;
			long long rest_time = f_time - b_time;
			ans += rest_time * c[i];
			prev_stop_pos = x[i];
		}
	}
 
	ofstream("reststops.out") << ans << endl;
}

import java.io.*;
 
public class RestStops {
	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new FileReader("reststops.in"));
 
		String[] line = br.readLine().split(" ");
		int trailLen = Integer.parseInt(line[0]);  // nunca se usa
		int stopNum = Integer.parseInt(line[1]);
		int fRate = Integer.parseInt(line[2]);
		int bRate = Integer.parseInt(line[3]);
 
		int[] x = new int[stopNum];  // posición de cada parada
		int[] c = new int[stopNum];  // valor de sabor de cada parada
 
		for (int i = 0; i < stopNum; i++) {
			line = br.readLine().split(" ");
			x[i] = Integer.parseInt(line[0]);
			c[i] = Integer.parseInt(line[1]);
		}
		br.close();
 
		// hallamos todas las paradas "mejores"
		boolean[] good = new boolean[stopNum];
		int maxTastiness = 0;
		for (int i = stopNum - 1; i >= 0; i--) {
			if (c[i] > maxTastiness) {
				// no hay paradas después de i que sean "mejores"
				good[i] = true;
				maxTastiness = c[i];
			}
		}
 
		// simulamos todo el sendero
		int prevStopPos = 0;
		long ans = 0;
		for (int i = 0; i < stopNum; i++) {
			if (good[i]) {
				long travelDist = x[i] - prevStopPos;
				long fTime = travelDist * fRate;
				long bTime = travelDist * bRate;
				long restTime = fTime - bTime;
				ans += restTime * c[i];
				prevStopPos = x[i];
			}
		}
 
		PrintWriter pw = new PrintWriter("reststops.out");
		pw.println(ans);
		pw.close();
	}
}

with open("reststops.in") as read:
	# trail_len no se usa
	trail_len, stop_num, f_rate, b_rate = [int(i) for i in read.readline().split()]
 
	x = []  # posición de cada parada
	c = []  # valor de sabor de cada parada
	for _ in range(stop_num):
		a, b = [int(i) for i in read.readline().split()]
		x.append(a)
		c.append(b)
 
# hallamos todas las paradas "mejores"
good = [False for _ in range(stop_num)]
max_tastiness = 0
for i in range(stop_num - 1, -1, -1):
	if c[i] > max_tastiness:
		# no hay paradas después de i que sean "mejores"
		good[i] = True
		max_tastiness = c[i]
 
# simulamos todo el sendero
prev_stop_pos = 0
ans = 0
for i in range(stop_num):
	if good[i]:
		travel_dist = x[i] - prev_stop_pos
		f_time = travel_dist * f_rate
		b_time = travel_dist * b_rate
		rest_time = f_time - b_time
		ans += rest_time * c[i]
		prev_stop_pos = x[i]
 
print(ans, file=open("reststops.out", "w"))