#10115. 「一本通 4.1 例 3」校门外的树

https://loj.ac/s/1025566

LibreOJ/10115/10115.cpp

@@ -0,0 +1,55 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int n, m, op, l, r, c1[1000001], c2[1000001];
+
+int lowbit(int x) {
+    return x & (-x);
+}
+
+inline void update1(int x, int v) {
+    while (x <= n) {
+        c1[x] += v;
+        x += lowbit(x);
+    }
+}
+
+inline void update2(int x, int v) {
+    while (x <= n) {
+        c2[x] += v;
+        x += lowbit(x);
+    }
+}
+
+int sum1(int x) {
+    int p = 0;
+    while (x > 0) {
+        p += c1[x];
+        x -= lowbit(x);
+    }
+    return p;
+}
+
+int sum2(int x) {
+    int p = 0;
+    while (x > 0) {
+        p += c2[x];
+        x -= lowbit(x);
+    }
+    return p;
+}
+
+int main() {
+    cin >> n >> m;
+    for (int i = 1; i <= m; i++) {
+        cin >> op >> l >> r;
+        if (op == 1) {
+            update1(l, 1), update2(r, 1);
+        }
+        if (op == 2) {
+            cout << sum1(r) - sum2(l - 1) << endl;
+        }
+    }
+    return 0;
+}