diff --git a/problem/P2574/P2574.cpp b/problem/P2574/P2574.cpp
new file mode 100644
index 00000000..5a765aeb
--- /dev/null
+++ b/problem/P2574/P2574.cpp
@@ -0,0 +1,90 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+struct node {
+    int l, r;
+    int s, d;
+    node() {
+        l = r = s = d = 0;
+    }
+    node(int _l, int _r) {
+        l = _l;
+        r = _r;
+        s = d = 0;
+    }
+} tr[200005 << 2];
+int n, m, op, x, y, a[200005];
+
+void pushup(int u) {
+    tr[u].s = tr[u << 1].s + tr[u << 1 | 1].s;
+}
+
+void pushdown(int u) {
+    if (tr[u].d) {
+        tr[u << 1].d ^= tr[u].d;
+        tr[u << 1].s = (tr[u << 1].r - tr[u << 1].l + 1) - tr[u << 1].s;
+        tr[u << 1 | 1].d ^= tr[u].d;
+        tr[u << 1 | 1].s = (tr[u << 1 | 1].r - tr[u << 1 | 1].l + 1) - tr[u << 1 | 1].s;
+        tr[u].d = 0;
+    }
+}
+
+void build(int u, int l, int r) {
+    tr[u] = node(l, r);
+    if (l == r) {
+        tr[u].s = a[l];
+        return;
+    }
+    int mid = l + r >> 1;
+    build(u << 1, l, mid);
+    build(u << 1 | 1, mid + 1, r);
+    pushup(u);
+}
+
+void modify(int u, int l, int r) {
+    if (tr[u].l >= l && tr[u].r <= r) {
+        tr[u].d ^= 1;
+        tr[u].s = (tr[u].r - tr[u].l + 1) - tr[u].s;
+        return;
+    }
+    int mid = tr[u].l + tr[u].r >> 1;
+    pushdown(u);
+    if (l <= mid) {
+        modify(u << 1, l, r);
+    }
+    if (r > mid) {
+        modify(u << 1 | 1, l, r);
+    }
+    pushup(u);
+}
+
+int query(int u, int l, int r) {
+    if (tr[u].l >= l && tr[u].r <= r) {
+        return tr[u].s;
+    }
+    int mid = tr[u].l + tr[u].r >> 1;
+    int s = 0;
+    pushdown(u);
+    if (l <= mid) s += query(u << 1, l, r);
+    if (r > mid) s += query(u << 1 | 1, l, r);
+    return s;
+}
+
+int main() {
+    cin >> n >> m;
+    for (int i = 1; i <= n; i++) {
+        scanf("%1d", &a[i]);
+    }
+    build(1, 1, n);
+    while (m--) {
+        cin >> op >> x >> y;
+        if (op == 0) {
+            modify(1, x, y);
+        }
+        else if (op == 1) {
+            cout << query(1, x, y) << endl;
+        }
+    }
+    return 0;
+}