atcoder/abc076D

Author: xirc

atcoder/abc076/D/main.cpp

@@ -0,0 +1,60 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+using ll = long long;
+
+int N;
+vector<int> ts;
+vector<int> vs;
+
+double solve() {
+    int T = 0;
+    vector<vector<int>> cs(N);
+    for (int i = 0; i < N; ++i) {
+        int l = T, r = T + ts[i], v = vs[i];
+        cs[i] = { l, r, v };
+        T += ts[i];
+    }
+    cs.push_back({ 0, 0, 0 });
+    cs.push_back({ T, T, 0 });
+    const auto minv = [&](double t) {
+        double res = 100;
+        for (auto const& c : cs) {
+            auto l = c[0], r = c[1], v = c[2];
+            if (t < l) {
+                res = min(res, v + (l - t));
+            } else if (t > r) {
+                res = min(res, v + (t - r));
+            } else {
+                res = min(res, double(v));
+            }
+        }
+        return res;
+    };
+
+    double S = 0;
+    for (int tt = 0; tt < 2 * T; ++tt) {
+        double t = tt * 0.5, nt = (tt + 1) * 0.5;
+        double v = minv(t), nv = minv(nt);
+        S += 0.5 * (v + nv) * 0.5;
+    }
+    return S;
+}
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(0); cout.tie(0);
+
+    cin >> N;
+    ts.assign(N, 0);
+    vs.assign(N, 0);
+    for (int i = 0; i < N; ++i) {
+        cin >> ts[i];
+    }
+    for (int i = 0; i < N; ++i) {
+        cin >> vs[i];
+    }
+    cout << fixed << setprecision(3) << solve() << endl;
+
+    return 0;
+}