Lennot

__import__("sys").setrecursionlimit(10000)

def rec_price(city,free,paid_cities,dpaid_cities):
    p=2147483647
    if city==n:
        return 0
    for f in flights[city]:
        if f[0] not in dpaid_cities:
            t,d=paid_cities[:],dpaid_cities[:]
            if not free:
                if city in t:
                    d+=[city]
                else:
                    t+=[city]
            x=rec_price(f[0],not free,t,d)+f[1]*(not free)
            p=min(p,x)
    return p

def ite_price(city=1):
    free = False
    paid_cities = [0 for _ in range(n+1)]
    cities = []
    prices = [2147483647]
    fprices = []
    iteras = []
    i = 0
    depth = 1
    added = 0
    while depth > 0:
        added = 0
        flightlist = flights[city]
        if city == n:
            prices[-1]=0
        else:
            while i < len(flightlist):
                f = flightlist[i]
                if paid_cities[f[0]] < 2:
                    if not free:
                        paid_cities[f[0]]+=1
                        fprices += [f[1]]
                    else:
                        fprices += [0]
                    added = 1
                    cities += [city]
                    iteras += [i+1]
                    if len(prices) <= depth:
                        prices += [2147483647]
                    city=f[0]
                    i=0
                    depth+=1
                    free = not free
                    break
                i += 1
        if not added:
            if depth > 1:
                free = not free
                if not free:
                    paid_cities[city]-=1
                i = iteras[-1]
                pr = prices[-1]
                fp = fprices[-1]
                city = cities[-1]
                iteras = iteras[:-1]
                prices = prices[:-1]
                fprices = fprices[:-1]
                cities = cities[:-1]
                prices[-1] = min(prices[-1],pr+fp)
            depth -= 1
    return prices[0]

n,m=map(int,input().split(" "))

flights=[[] for _ in range(n+1)]

for i in range(m):
    l=list(map(int,input().split(" ")))
    flights[l[0]]+=[l[1:]]

rec = False
if rec:
    print(rec_price(1,False,[],[]))
else:
    print(ite_price())

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: TIME LIMIT EXCEEDED

Test 7

Group: 2

Verdict: TIME LIMIT EXCEEDED

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