P4396 [AHOI2013]作业

https://www.luogu.com.cn/record/76786462

Luogu/P4396/P4396.cpp

@@ -0,0 +1,88 @@
+#include <iostream>
+#include <algorithm>
+#include <cmath>
+#include <tuple>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5;
+
+int n, m, w[N], c[N], c1[N], c2[N], t;
+std::pair<int, int> now, ans[N];
+std::vector<std::tuple<int, int, int, int, int>> q;
+
+inline int lowbit(int x) {
+    return x & -x;
+}
+
+void add(int *c, int x, int y) {
+    for (; x <= n; x += lowbit(x)) c[x] += y;
+}
+
+int sum(int *c, int x) {
+    int res = 0;
+    for (; x; x -= lowbit(x)) res += c[x];
+    return res;
+}
+
+void add(int x) {
+    if (!c[x]++) add(c1, x, 1);
+    add(c2, x, 1);
+}
+
+void del(int x) {
+    if (!--c[x]) add(c1, x, -1);
+    add(c2, x, -1);
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> m;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> w[i];
+    }
+
+    t = sqrt(n);
+
+    for (int i = 1, l, r, a, b; i <= m; i++) {
+        cin >> l >> r >> a >> b;
+
+        q.push_back(std::make_tuple(i, l, r, a, b));
+    }
+
+    std::sort(q.begin(), q.end(), [&](auto a, auto b) {
+        int p = std::get<1>(a) / t,
+            q = std::get<1>(b) / t;
+        int x = std::get<2>(a),
+            y = std::get<2>(b);
+
+        return p == q
+                 ? p & 1 ? x < y : x > y
+                 : p < q;
+    });
+
+    int i = 0, j = 1;
+    for (auto &e : q) {
+        int id, l, r, a, b;
+        std::tie(id, l, r, a, b) = e;
+
+        while (i < r) add(w[++i]);
+        while (i > r) del(w[i--]);
+        while (j < l) del(w[j++]);
+        while (j > l) add(w[--j]);
+
+        ans[id] = std::make_pair(sum(c2, b) - sum(c2, a - 1), sum(c1, b) - sum(c1, a - 1));
+    }
+
+    for (int i = 1; i <= m; i++) {
+        cout << ans[i].first << ' ' << ans[i].second << endl;
+    }
+
+    return 0;
+}