802. 区间和

https://www.acwing.com/problem/content/submission/code_detail/10681087/

AcWing/802/802.cpp

@@ -0,0 +1,43 @@
+#include <algorithm>
+#include <iostream>
+#include <vector>
+
+using std::cin;
+using std::cout;
+#define endl '\n'
+
+int n, m, x, c, l, r, data[300005], sum[300005];
+std::vector<int> nums;
+std::vector<std::pair<int, int>> adds, queries;
+
+inline int find(int x) {
+    auto pos = std::lower_bound(nums.begin(), nums.end(), x);
+    return pos == nums.end() || *pos != x ? 0 : pos - nums.begin() + 1;
+}
+
+int main() {
+    cin >> n >> m;
+    for (int i = 1; i <= n; i++) {
+        cin >> x >> c;
+        nums.push_back(x);
+        adds.push_back(std::make_pair(x, c));
+    }
+    for (int i = 1; i <= m; i++) {
+        cin >> l >> r;
+        queries.push_back(std::make_pair(l, r));
+        nums.push_back(l);
+        nums.push_back(r);
+    }
+    std::sort(nums.begin(), nums.end());
+    nums.erase(std::unique(nums.begin(), nums.end()), nums.end());
+    for (const auto& add : adds) {
+        data[find(add.first)] += add.second;
+    }
+    for (int i = 1; i <= nums.size(); i++) {
+        sum[i] = sum[i - 1] + data[i];
+    }
+    for (const auto& query : queries) {
+        cout << sum[find(query.second)] - sum[find(query.first) - 1] << endl;
+    }
+    return 0;
+}