From e97574f3e5632968b49ad61c6c344fe828bc403e Mon Sep 17 00:00:00 2001
From: Baoshuo <i@baoshuo.ren>
Date: Tue, 16 Jul 2024 08:17:50 +0800
Subject: [PATCH] =?UTF-8?q?P1638=20=E9=80=9B=E7=94=BB=E5=B1=95?=
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https://www.luogu.com.cn/record/166266843
---
 Luogu/P1638/P1638.cpp | 61 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 Luogu/P1638/P1638.cpp

diff --git a/Luogu/P1638/P1638.cpp b/Luogu/P1638/P1638.cpp
new file mode 100644
index 00000000..40fc0c76
--- /dev/null
+++ b/Luogu/P1638/P1638.cpp
@@ -0,0 +1,61 @@
+#include <iostream>
+#include <limits>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e6 + 5,
+          M = 2e3 + 5;
+
+int n, m, a[N];
+int cnt, b[M];  // 记录出现过的数
+int ans, ans_l, ans_r;
+
+void insert(int x) {
+    if (b[x] == 0) cnt++;  // 维护数的数目
+    b[x]++;                // 维护数的出现次数
+}
+
+void erase(int x) {
+    b[x]--;                // 维护数的出现次数
+    if (b[x] == 0) cnt--;  // 维护数的数目
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> m;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+    }
+
+    ans = std::numeric_limits<int>::max();
+
+    for (int i = 1, j = 1; i <= n; i++) {
+        insert(a[i]);  // 先维护右指针
+
+        while (true) {
+            erase(a[j]);
+
+            if (cnt == m) {  // 删了以后还是满足条件
+                j++;         // 维护左指针
+            } else {
+                insert(a[j]);  // 恢复
+                break;
+            }
+        }
+
+        if (cnt == m && i - j + 1 < ans) {  // 记录答案
+            ans = i - j + 1;
+            ans_l = j;
+            ans_r = i;
+        }
+    }
+
+    cout << ans_l << ' ' << ans_r << endl;
+
+    return 0;
+}