結果
| 問題 | No.3307 Almost Equal | 
| コンテスト | |
| ユーザー |  | 
| 提出日時 | 2025-10-05 14:57:17 | 
| 言語 | PyPy3 (7.3.15) | 
| 結果 | 
                                AC
                                 
                             | 
| 実行時間 | 48 ms / 2,000 ms | 
| コード長 | 3,082 bytes | 
| コンパイル時間 | 163 ms | 
| コンパイル使用メモリ | 82,104 KB | 
| 実行使用メモリ | 57,224 KB | 
| 最終ジャッジ日時 | 2025-10-05 14:57:31 | 
| 合計ジャッジ時間 | 3,844 ms | 
| ジャッジサーバーID (参考情報) | judge5 / judge2 | 
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| ファイルパターン | 結果 | 
|---|---|
| sample | AC * 3 | 
| other | AC * 46 | 
ソースコード
# input
import sys
input = sys.stdin.readline
II = lambda : int(input())
MI = lambda : map(int, input().split())
LI = lambda : [int(a) for a in input().split()]
SI = lambda : input().rstrip()
LLI = lambda n : [[int(a) for a in input().split()] for _ in range(n)]
LSI = lambda n : [input().rstrip() for _ in range(n)]
MI_1 = lambda : map(lambda x:int(x)-1, input().split())
LI_1 = lambda : [int(a)-1 for a in input().split()]
mod = 998244353
inf = 1001001001001001001
ordalp = lambda s : ord(s)-65 if s.isupper() else ord(s)-97
ordallalp = lambda s : ord(s)-39 if s.isupper() else ord(s)-97
yes = lambda : print("Yes")
no = lambda : print("No")
yn = lambda flag : print("Yes" if flag else "No")
prinf = lambda ans : print(ans if ans < 1000001001001001001 else -1)
alplow = "abcdefghijklmnopqrstuvwxyz"
alpup = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
alpall = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
URDL = {'U':(-1,0), 'R':(0,1), 'D':(1,0), 'L':(0,-1)}
DIR_4 = [[-1,0],[0,1],[1,0],[0,-1]]
DIR_8 = [[-1,0],[-1,1],[0,1],[1,1],[1,0],[1,-1],[0,-1],[-1,-1]]
DIR_BISHOP = [[-1,1],[1,1],[1,-1],[-1,-1]]
prime60 = [2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59]
sys.set_int_max_str_digits(0)
# sys.setrecursionlimit(10**6)
# import pypyjit
# pypyjit.set_param('max_unroll_recursion=-1')
from collections import defaultdict,deque
from heapq import heappop,heappush
from bisect import bisect_left,bisect_right
DD = defaultdict
BSL = bisect_left
BSR = bisect_right
def floor_sum(n, m, a, b):
    """
    sum_{0 <= i <= n - 1} floor(a * i + b / m)
    """
    res = 0
    while n:
        if a < 0 or m <= a:
            k, a = divmod(a, m)
            res += n*(n-1) * k >> 1
        if b < 0 or m <= b:
            k, b = divmod(b, m)
            res += n * k
        n, b = divmod(a*n+b, m)
        a, m = m, a
    return res
# https://qiita.com/sounansya/items/51b39e0d7bf5cc194081
def floor_sum_pq(n, m, a, b):
    """
    (p, q) = (0, 1), (0, 2), (1, 1) 
    """
    if m == 0:
        return 0, 0, 0
    a1, a2 = divmod(a, m)
    b1, b2 = divmod(b, m)
    y = (a2 * n + b2) // m
    s01, s02, s11 = floor_sum_pq(y, a2, m, m + a2 - b2 - 1)
    nn = n * (n - 1) // 2
    r01 = n * y - s01
    r02 = n * y * y - s01 - 2 * s11
    r11 = nn * y + (s01 - s02) // 2
    r02 += n * (2 * n - 1) * (n - 1) * a1 * a1 // 6
    r02 += 2 * nn * a1 * b1
    r02 += b1 * b1 * n
    r02 += 2 * a1 * r11
    r02 += 2 * b1 * r01
    r01 += a1 * nn + b1 * n
    r11 += nn * (a1 * (2 * n - 1) + 3 * b1) // 3
    return r01, r02, r11
a, b, c, d = MI()
if a * d == b * c:
    print(-1)
    exit()
if a * d < b * c:
    a, c = c, a
    b, d = d, b
b2 = b // 2
d2 = d // 2
def calc(u):
    return (a * u + b2) * d - (c * u + d2) * b < b * d
ok = 0
ng = 10 ** 18
while ng - ok > 1:
    m = ok + ng >> 1
    if calc(m):
        ok = m
    else:
        ng = m
# print(ok, ng)
u = ok + 1
k = floor_sum(u, b, a, b2) - floor_sum(u, d, c, d2)
# print(u, k)
# for i in range(u):
#     k = floor_sum(i, b, a, b2) - floor_sum(i, d, c, d2)
#     print(i, i - 1 - k)
print(u - 1 - abs(k))
            
            
            
        