From d8dd0c81b14bc00a36b01f83c00b8eb1cf237779 Mon Sep 17 00:00:00 2001
From: Zengtudor <Zengtudor@outlook.com>
Date: Sat, 23 Aug 2025 13:57:11 +0800
Subject: [PATCH] update

---
 src/8/23/P3939.cpp | 63 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 src/8/23/P3939.cpp

diff --git a/src/8/23/P3939.cpp b/src/8/23/P3939.cpp
new file mode 100644
index 0000000..6ab9e10
--- /dev/null
+++ b/src/8/23/P3939.cpp
@@ -0,0 +1,63 @@
+#include <algorithm>
+#include <iostream>
+#include <vector>
+
+void fast_io() {
+    std::ios_base::sync_with_stdio(false);
+    std::cin.tie(nullptr);
+}
+
+const int MAXN = 300005;
+
+int n, m;
+int a[MAXN];
+std::vector<int> pos[MAXN];
+
+int main() {
+    fast_io();
+
+    std::cin >> n >> m;
+    for (int i = 1; i <= n; ++i) {
+        std::cin >> a[i];
+        pos[a[i]].push_back(i);
+    }
+
+    for (int i = 0; i < m; ++i) {
+        int op;
+        std::cin >> op;
+        if (op == 1) {
+
+            int l, r, c;
+            std::cin >> l >> r >> c;
+
+            auto it_l = std::lower_bound(pos[c].begin(), pos[c].end(), l);
+            auto it_r = std::upper_bound(pos[c].begin(), pos[c].end(), r);
+
+            std::cout << (it_r - it_l) << "\n";
+
+        } else {
+
+            int x;
+            std::cin >> x;
+
+            int c1 = a[x];
+            int c2 = a[x + 1];
+
+            if (c1 == c2) {
+                continue;
+            }
+
+            auto it1 = std::lower_bound(pos[c1].begin(), pos[c1].end(), x);
+
+            *it1 = x + 1;
+
+            auto it2 = std::lower_bound(pos[c2].begin(), pos[c2].end(), x + 1);
+
+            *it2 = x;
+
+            std::swap(a[x], a[x + 1]);
+        }
+    }
+
+    return 0;
+}