Submission #7296129


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import sys
readline = sys.stdin.readline

N, M = map(int, readline().split())
INF = 10**18
C = [INF]*N
C[1:N-1] = map(int, readline().split())

from collections import deque
class PushRelabel:
    def __init__(self, N):
        self.N = N
        self.G = [[] for i in range(N)]
        self.initial = [N]*N
        self.zeros = [0]*(N+1)

    def add_edge(self, fr, to, cap):
        forward = [to, cap, None]
        forward[2] = backward = [fr, 0, forward]
        self.G[fr].append(forward)
        self.G[to].append(backward)

    def add_multi_edge(self, v1, v2, cap1, cap2):
        edge1 = [v2, cap1, None]
        edge1[2] = edge2 = [v1, cap2, edge1]
        self.G[v1].append(edge1)
        self.G[v2].append(edge2)

    # Global labeling
    def bfs(self, H, D, t, que=deque()):
        que.append(t)
        G = self.G
        H[:] = self.initial
        H[t] = 0
        D[:] = self.zeros
        D[0] = 1
        c = N-1
        while que:
            v = que.popleft()
            d = H[v] + 1
            for w, cap, backward in G[v]:
                if H[w] <= d or backward[1] == 0:
                    continue
                H[w] = d
                D[d] += 1
                c -= 1
                que.append(w)
        D[N] = c
        return d # gap

    # FIFO preflow-push algorithm
    def flow(self, s, t):
        N = self.N
        H = [0]*N # height
        F = [0]*N # excess flow
        D = [0]*(N+1) # distance label
        active = [0]*N # active node

        G = self.G

        que = deque([s])
        F[s] = 10**18
        active[s] = 1

        gap = self.bfs(H, D, t)

        cnt = 0
        while que:
            v = que.popleft()
            if v == t:
                continue

            hv = H[v]
            # Gap-relabeling
            if hv > gap:
                D[hv] -= 1
                D[N] += 1
                hv = H[v] = N
                continue
            # push
            rest = F[v]
            for e in G[v]:
                w, cap, backward = e
                if cap and hv > H[w] < gap:
                    d = min(rest, cap)
                    e[1] -= d
                    backward[1] += d
                    rest -= d
                    F[w] += d
                    if not active[w]:
                        que.append(w)
                        active[w] = 1
                    if rest == 0:
                        break
            F[v] = rest

            if rest == 0:
                active[v] = 0
                continue

            # relabel
            h0 = H[v]
            hv = N
            for w, cap, backward in G[v]:
                if cap and hv > H[w] + 1 <= gap:
                    hv = H[w] + 1
            if hv != h0:
                D[h0] -= 1
                if D[h0] == 0 and h0 < gap:
                    gap = h0
                    hv = N
                elif hv == gap:
                    gap += 1
                D[hv] += 1

            H[v] = hv
            if hv < N:
                que.append(v)
            else:
                active[v] = 0

            cnt += 1
            if cnt % N == 0:
                gap = self.bfs(H, D, t)
        return F[t]

pl = PushRelabel(2*N+2)
ok = 1
for i in range(M):
    a, b = map(int, readline().split()); a -= 1; b -= 1
    if C[a] == C[b] == -1:
        ok = 0
        break
    pl.add_edge(2*a+1, 2*b, INF)
for i in range(N):
    if C[i] == -1:
        pl.add_edge(2*i, 2*N+1, INF)
        pl.add_edge(2*N, 2*i+1, INF)
    else:
        pl.add_edge(2*i, 2*i+1, C[i])
if not ok:
    sys.stdout.write("-1\n")
    exit(0)
sys.stdout.write("%d\n" % pl.flow(2*N, 2*N+1))

Submission Info

Submission Time
Task F - RPG
User yaketake08
Language PyPy3 (2.4.0)
Score 200
Code Size 3773 Byte
Status
Exec Time 239 ms
Memory 43760 KB

Test Cases

Set Name Score / Max Score Test Cases
All 200 / 200 0-sample-1, 0-sample-2, 1-random-small-0, 1-random-small-1, 1-random-small-2, 1-random-small-3, 2-random-large-0, 2-random-large-1, 2-random-large-2, 2-random-large-3, 2-random-large-4, 2-random-large-5, 2-random-large-6, 2-random-large-7, 2-random-large-8, 2-random-large-9, 3-line-0, 3-line-1, 3-line-2, 3-line-3, 4-special-0, 4-special-1, 5-comp-0, 5-comp-1, 5-comp-2, 9-hand-0, 9-hand-1, 9-hand-2, 9-hand-3, 9-hand-4, 9-hand-5
Case Name Status Exec Time Memory
0-sample-1 168 ms 38384 KB
0-sample-2 162 ms 38256 KB
1-random-small-0 162 ms 38256 KB
1-random-small-1 161 ms 38256 KB
1-random-small-2 161 ms 38256 KB
1-random-small-3 160 ms 38256 KB
2-random-large-0 161 ms 38256 KB
2-random-large-1 210 ms 42608 KB
2-random-large-2 164 ms 38256 KB
2-random-large-3 183 ms 39792 KB
2-random-large-4 165 ms 38256 KB
2-random-large-5 217 ms 43376 KB
2-random-large-6 161 ms 38256 KB
2-random-large-7 208 ms 42352 KB
2-random-large-8 169 ms 38256 KB
2-random-large-9 210 ms 42096 KB
3-line-0 166 ms 38256 KB
3-line-1 214 ms 42992 KB
3-line-2 218 ms 42992 KB
3-line-3 162 ms 38256 KB
4-special-0 239 ms 43760 KB
4-special-1 226 ms 43504 KB
5-comp-0 170 ms 38256 KB
5-comp-1 171 ms 38768 KB
5-comp-2 170 ms 38256 KB
9-hand-0 163 ms 38256 KB
9-hand-1 171 ms 38384 KB
9-hand-2 172 ms 38256 KB
9-hand-3 161 ms 38256 KB
9-hand-4 162 ms 38256 KB
9-hand-5 161 ms 38256 KB