Problem p02941 (python)

Fixed submission:
from pprint import pprint
import heapq

def solve(n, a, b):
    b_pq = []
    b_rev = {}
    delete = []
    for i, b_i in enumerate(b):
        if b_i == a[i]:
            continue
        heapq.heappush(b_pq, (-1 * b_i, i))

    count = 0
    while b_pq:
        tmp = heapq.heappop(b_pq)
        # pprint(tmp)
        b_i = tmp[0] * -1
        i_b = tmp[1]
        # print(i_b, b_i)
        i_a = (i_b - 1 + n) % n
        i_c = (i_b + 1) % n
        b_cand = b_i
        if b_cand - b[i_a] - b[i_c] < a[i_b]:
            continue

        #while b_cand - b[i_a] - b[i_c] >= a[i_b]:
        #    b_cand = b_cand - b[i_a] - b[i_c]
        #    count += 1
        tmp_count =  (b_cand - a[i_b]) // (b[i_a] + b[i_c])
        b_cand -= (b[i_a] + b[i_c]) * tmp_count
        count += tmp_count

        b[i_b] = b_cand
        if b_cand != a[i_b]:
            heapq.heappush(b_pq, (-1 * b_cand, i_b))
        # print("count: ", count)
        # pprint(b)
         

        if b_cand == a[i_b] and b == a:
            return count
    
    return -1


if __name__ == '__main__':

    n = int(input().strip())
    a = list(map(int, input().strip().split(" ")))
    b = list(map(int, input().strip().split(" ")))
    print(solve(n, a, b))

Buggy submission (verdict: Runtime Error):
from pprint import pprint
import heapq

def solve(n, a, b):
    b_pq = []
    b_rev = {}
    delete = []
    for i, b_i in enumerate(b):
        if b_i == a[i]:
            delete.append(i)
            continue
        heapq.heappush(b_pq, (-1 * b_i, i))

    for i in sorted(delete, reverse=True):
        a.pop(i)

    count = 0
    while b_pq:
        tmp = heapq.heappop(b_pq)
        # pprint(tmp)
        b_i = tmp[0] * -1
        i_b = tmp[1]
        # print(i_b, b_i)
        i_a = (i_b - 1 + n) % n
        i_c = (i_b + 1) % n
        b_cand = b_i
        if b_cand - b[i_a] - b[i_c] < a[i_b]:
            continue

        #while b_cand - b[i_a] - b[i_c] >= a[i_b]:
        #    b_cand = b_cand - b[i_a] - b[i_c]
        #    count += 1
        tmp_count =  (b_cand - a[i_b]) // (b[i_a] + b[i_c])
        b_cand -= (b[i_a] + b[i_c]) * tmp_count
        count += tmp_count

        b[i_b] = b_cand
        heapq.heappush(b_pq, (-1 * b_cand, i_b))
        # print("count: ", count)
        # pprint(b)
        if b_cand == a[i_b] and b == a:
            return count
    
    return -1


if __name__ == '__main__':

    n = int(input().strip())
    a = list(map(int, input().strip().split(" ")))
    b = list(map(int, input().strip().split(" ")))
    print(solve(n, a, b))

Buggy submission (verdict: Runtime Error):
from pprint import pprint
import heapq

def solve(n, a, b):
    b_pq = []
    b_rev = {}
    for i, b_i in enumerate(b):
        if b_i == a[i]:
            a.pop(i)
            continue
        heapq.heappush(b_pq, (-1 * b_i, i))

    count = 0
    while b_pq:
        tmp = heapq.heappop(b_pq)
        # pprint(tmp)
        b_i = tmp[0] * -1
        i_b = tmp[1]
        # print(i_b, b_i)
        i_a = (i_b - 1 + n) % n
        i_c = (i_b + 1) % n
        b_cand = b_i
        if b_cand - b[i_a] - b[i_c] < a[i_b]:
            continue

        #while b_cand - b[i_a] - b[i_c] >= a[i_b]:
        #    b_cand = b_cand - b[i_a] - b[i_c]
        #    count += 1
        tmp_count =  (b_cand - a[i_b]) // (b[i_a] + b[i_c])
        b_cand -= (b[i_a] + b[i_c]) * tmp_count
        count += tmp_count

        b[i_b] = b_cand
        heapq.heappush(b_pq, (-1 * b_cand, i_b))
        # print("count: ", count)
        # pprint(b)
        if b_cand == a[i_b] and b == a:
            return count
    
    return -1


if __name__ == '__main__':

    n = int(input().strip())
    a = list(map(int, input().strip().split(" ")))
    b = list(map(int, input().strip().split(" ")))
    print(solve(n, a, b))

Buggy submission (verdict: Runtime Error):
from pprint import pprint
import heapq

def solve(n, a, b):
    b_pq = []
    b_rev = {}
    for i, b_i in enumerate(b):
        heapq.heappush(b_pq, (-1 * b_i, i))

    count = 0
    while b_pq:
        tmp = heapq.heappop(b_pq)
        # pprint(tmp)
        b_i = tmp[0] * -1
        i_b = tmp[1]
        # print(i_b, b_i)
        i_a = (i_b - 1 + n) % n
        i_c = (i_b + 1) % n
        b_cand = b_i
        if b_cand - b[i_a] - b[i_c] < a[i_b]:
            continue

        #while b_cand - b[i_a] - b[i_c] >= a[i_b]:
        #    b_cand = b_cand - b[i_a] - b[i_c]
        #    count += 1
        tmp_count =  b_cand // (b[i_a] + b[i_c])
        b_cand -= (b[i_a] + b[i_c]) * tmp_count
        count += tmp_count

        b[i_b] = b_cand
        heapq.heappush(b_pq, (-1 * b_cand, i_b))
        # print("count: ", count)
        # pprint(b)
        if b_cand == a[i_b] and b == a:
            return count
    
    return -1


if __name__ == '__main__':

    n = int(input().strip())
    a = list(map(int, input().strip().split(" ")))
    b = list(map(int, input().strip().split(" ")))
    print(solve(n, a, b))