Lennot

import java.util.ArrayList;
import java.util.List;

public class Lents4 {
	static int cityCount, flightCount;
	
	static int[][] flights;
	static long[] costs;
	
	static long[][] kaijjutin;
	
	public static List<Integer> getFlightsFrom(int from) {
		List<Integer> result = new ArrayList<Integer>();
		
		for(int i = 0; i < flightCount; i++)
			if(flights[i][0] == from)
				result.add(flights[i][1]);
		
		return result;
	}
	
	public static long getLowestCost(int from, int to) {
		long result = Long.MAX_VALUE;
		
		for(int i = 0; i < flightCount; i++)
			if(flights[i][0] == from && flights[i][1] == to && costs[i] < result)
				result = costs[i];
		
		if(result == Long.MAX_VALUE) Integer.parseInt("no");
		return result;
	}
	
	public static void main(String[] args) {
		IO oi = new IO();
		
		cityCount = oi.nextInt();
		flightCount = oi.nextInt();
		
		flights = new int[flightCount][2];
		costs = new long[flightCount];
		kaijjutin = new long[cityCount][2];
		
		for(int i = 0; i < flightCount; i++) {
			flights[i] = new int[] { oi.nextInt()-1, oi.nextInt()-1 };
			costs[i] = oi.nextLong();
			
			if(i < cityCount) kaijjutin[i] = new long[] { 0, -1 };
		}
		
		kaijjutin[0][1] = 0;
		
		List<Integer> goThrough = new ArrayList<Integer>();
		goThrough.add(0);
		
		int from;
		long addedPrice;
		
		while(true) {
			if(goThrough.isEmpty()) break;
			
			from = goThrough.get(0);
			goThrough.remove(0);
			
			for(int to : getFlightsFrom(from)) {
				addedPrice = kaijjutin[from][0] % 2 == 1 ? 0 : getLowestCost(from, to);
				
				if(kaijjutin[to][0] <= flightCount) {
					if(to == cityCount-1 && (kaijjutin[from][1] + addedPrice < kaijjutin[to][1] || kaijjutin[to][1] == -1)) {
						kaijjutin[to][1] = kaijjutin[from][1] + addedPrice;
					} else if(to != cityCount-1) {
						kaijjutin[to][0] = kaijjutin[from][0] + 1;
						kaijjutin[to][1] = kaijjutin[from][1] + addedPrice;
						
						goThrough.add(to);
					}
				}
			}
		}
		
		oi.println(kaijjutin[cityCount-1][1]);
		oi.close();
	}
}

Test 1

Group: 1

Verdict: WRONG ANSWER

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: TIME LIMIT EXCEEDED

Test 4

Group: 1

Verdict: WRONG ANSWER

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 7

Group: 2

Verdict: WRONG ANSWER

Test 8

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 9

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 10

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 14

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 16

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 17

Group: 3

Verdict: TIME LIMIT EXCEEDED