499. 聪明的质监员

https://www.acwing.com/problem/content/submission/code_detail/9288330/

AcWing/499/499.cpp

@@ -0,0 +1,56 @@
+#include <bits/stdc++.h>
+
+using std::cin;
+using std::cout;
+using std::endl;
+
+int n, m, l, r, w[200005], v[200005];
+long long s, y, sum, ans, fn[200005], fv[200005];
+std::pair<int, int> q[200005];
+
+bool check(int x) {
+    y = sum = 0;
+    memset(fn, 0x00, sizeof(fn));
+    memset(fv, 0x00, sizeof(fv));
+    for (int i = 1; i <= n; i++) {
+        if (w[i] >= x) {
+            fn[i] = fn[i - 1] + 1;
+            fv[i] = fv[i - 1] + v[i];
+        } else {
+            fn[i] = fn[i - 1];
+            fv[i] = fv[i - 1];
+        }
+    }
+    for (int i = 1; i <= m; i++) {
+        y += (fn[q[i].second] - fn[q[i].first - 1]) * (fv[q[i].second] - fv[q[i].first - 1]);
+    }
+    sum = std::abs(y - s);
+    return y > s;
+}
+
+int main() {
+    ans = std::numeric_limits<long long>::max();
+    l = std::numeric_limits<int>::max();
+    r = std::numeric_limits<int>::min();
+    cin >> n >> m >> s;
+    for (int i = 1; i <= n; i++) {
+        cin >> w[i] >> v[i];
+        l = std::min(l, w[i]);
+        r = std::max(r, w[i]);
+    }
+    for (int i = 1; i <= m; i++) {
+        cin >> q[i].first >> q[i].second;
+    }
+    l -= 1, r += 2;
+    while (l <= r) {
+        int mid = l + r >> 1;
+        if (check(mid)) {
+            l = mid + 1;
+        } else {
+            r = mid - 1;
+        }
+        ans = std::min(ans, sum);
+    }
+    cout << ans << endl;
+    return 0;
+}