diff --git a/Luogu/P2801/P2801.cpp b/Luogu/P2801/P2801.cpp
new file mode 100644
index 00000000..f7945d0a
--- /dev/null
+++ b/Luogu/P2801/P2801.cpp
@@ -0,0 +1,101 @@
+#include <algorithm>
+#include <cmath>
+#include <iostream>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e6 + 5;
+
+int n, q, t, c, a[N], b[N], st[N], ed[N], pos[N], add[N];
+
+inline void process(int x) {
+    for (int i = st[x]; i <= ed[x]; i++) b[i] = a[i];
+    std::sort(b + st[x], b + ed[x] + 1);
+}
+
+void change(int l, int r, int c) {
+    int p = pos[l],
+        q = pos[r];
+
+    if (p == q) {
+        for (int i = l; i <= r; i++) a[i] += c;
+        process(p);
+
+        return;
+    }
+
+    for (int i = l; i <= ed[p]; i++) a[i] += c;
+    process(p);
+    for (int i = st[q]; i <= r; i++) a[i] += c;
+    process(q);
+    for (int i = p + 1; i <= q - 1; i++) add[i] += c;
+}
+
+int query(int l, int r, int c) {
+    int p = pos[l],
+        q = pos[r];
+    int cnt = 0;
+
+    if (p == q) {
+        for (int i = l; i <= r; i++) {
+            if (a[i] + add[p] < c) cnt++;
+        }
+
+        return cnt;
+    }
+
+    for (int i = l; i <= ed[p]; i++) {
+        if (a[i] + add[p] < c) cnt++;
+    }
+    for (int i = st[q]; i <= r; i++) {
+        if (a[i] + add[q] < c) cnt++;
+    }
+    for (int i = p + 1; i <= q - 1; i++) {
+        cnt += std::lower_bound(b + st[i], b + ed[i] + 1, c - add[i]) - b - st[i];
+    }
+
+    return cnt;
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+
+    cin >> n >> q;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+        b[i] = a[i];
+    }
+
+    t = std::sqrt(n);
+
+    for (c = 1;; c++) {
+        st[c] = (c - 1) * t + 1;
+        ed[c] = std::min(n, c * t);
+
+        if (c * t >= n) break;
+    }
+
+    for (int i = 1; i <= c; i++) {
+        for (int j = st[i]; j <= ed[i]; j++) {
+            pos[j] = i;
+        }
+        std::sort(b + st[i], b + ed[i] + 1);
+    }
+
+    while (q--) {
+        char op;
+        int l, r, w;
+        cin >> op >> l >> r >> w;
+
+        if (op == 'M') {
+            change(l, r, w);
+        } else {  // op == 'A'
+            cout << r - l + 1 - query(l, r, w) << endl;
+        }
+    }
+
+    return 0;
+}
diff --git a/Luogu/P2801/data/P2801_1.in b/Luogu/P2801/data/P2801_1.in
new file mode 100644
index 00000000..2f673288
--- /dev/null
+++ b/Luogu/P2801/data/P2801_1.in
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:4e84f6f2be68265a7b39f9d9d9b59078636eb979dbbc0a7c65222b40d31c614e
+size 151
diff --git a/Luogu/P2801/data/P2801_1.out b/Luogu/P2801/data/P2801_1.out
new file mode 100644
index 00000000..f3f205a4
--- /dev/null
+++ b/Luogu/P2801/data/P2801_1.out
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:9d1d5ca3a7aac275074dc875647edc9d0c3de810f04fa7799ae7885c35a3f7dd
+size 21