From dd8d4cb398df10750eb908e3e718422d280f76a3 Mon Sep 17 00:00:00 2001
From: Zengtudor <Zengtudor@outlook.com>
Date: Tue, 21 Oct 2025 16:44:48 +0800
Subject: [PATCH] =?UTF-8?q?fix(P4087):=20=E4=BF=AE=E5=A4=8D=E5=A5=B6?=
 =?UTF-8?q?=E7=89=9B=E8=AE=A1=E6=95=B0=E9=80=BB=E8=BE=91=E9=94=99=E8=AF=AF?=
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修正判断条件，确保在奶牛数量变化时正确计算答案。移除冗余变量just_one_was_max，使用wasmaxcnt和ismaxcnt更精确地跟踪数量变化。
---
 src/10/20/P4087.cpp | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/10/20/P4087.cpp b/src/10/20/P4087.cpp
index 0160678..d5f0fc2 100644
--- a/src/10/20/P4087.cpp
+++ b/src/10/20/P4087.cpp
@@ -32,10 +32,9 @@ int main() {
     for (ll i = 1; i <= n; i++) {
 
         ll max_num_before = num_cowcount.rbegin()->first;
-        bool just_one_was_max = num_cowcount.rbegin()->second==1;
 
         ll old_cownum = cow_num[c[i].c];
-
+        ll wasmaxcnt = num_cowcount[old_cownum];
         bool was_top = (old_cownum == max_num_before);
 
         num_cowcount[old_cownum]--;
@@ -47,12 +46,12 @@ int main() {
         cow_num[c[i].c] = new_cownum;
 
         num_cowcount[new_cownum]++;
-
+        ll ismaxcnt = num_cowcount[new_cownum];
         ll max_num_after = num_cowcount.rbegin()->first;
 
         bool is_top = (new_cownum == max_num_after);
 
-        if ((max_num_before != max_num_after && !just_one_was_max) || (was_top != is_top)) {
+        if ((was_top != is_top)||(was_top&is_top && wasmaxcnt!=ismaxcnt)) {
             ans++;
         }
     }