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pojcs101_M01922_ride_follower.cpp

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+#include <iostream>
+#include <vector>
+#include <algorithm>
+#include <cmath>
+
+using namespace std;
+
+typedef pair<int, int> Rider;
+
+constexpr int FULL_DISTANCE = 4500 * 3.6;
+
+int ride_time(const Rider& rider, const int distance = FULL_DISTANCE) {
+    return static_cast<int>(ceil(static_cast<double>(distance) / rider.first)) + rider.second;
+}
+
+int start_pos(const Rider& rider) {
+    if (rider.second >= 0) { return 0; }
+    return rider.first * -rider.second;
+}
+
+int arrival_time(const vector<Rider>& riders, const int distance = FULL_DISTANCE) {
+    vector<Rider> early_riders, late_riders;
+    for (const auto& rider : riders) {
+        if (rider.second >= 0) {
+            late_riders.push_back(rider);
+        } else {
+            // early_riders.push_back(rider);
+        }
+    }
+    double min_time = ride_time(*min_element(
+        late_riders.begin(), late_riders.end(),
+        [distance](const Rider& a, const Rider& b) {
+            return ride_time(a, distance) < ride_time(b, distance);
+        }));
+    clog << "min_time: " << min_time << endl;
+    // for (const auto& rider : early_riders) {
+    //     if (-rider.second > min_time) { continue; }
+    //     min_time = min(min_time, ride_time(rider, distance));
+    // }
+    return static_cast<int>(ceil(min_time));
+}
+
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+    int rider_count;
+    while (cin >> rider_count && rider_count) {
+        vector<Rider> riders(rider_count);
+        for (int i = 0; i < rider_count; i++) {
+            cin >> riders[i].first >> riders[i].second;
+            // riders[i].first /= 3.6;
+        }
+        cout << arrival_time(riders) << endl;
+    }
+
+    return 0;
+}