atcoder/abc052D

Author: xirc

atcoder/abc052/D/main.cpp

@@ -0,0 +1,45 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+using ll = long long;
+
+int N, A, B;
+vector<int> X;
+
+ll solve() {
+    vector<vector<int>> es;
+    for (int i = 1; i < N; ++i) {
+        int w = X[i] - X[i-1];
+        es.push_back({ w, i - 1, i });
+    }
+
+    vector<bool> has_next(N, false);
+    ll ans = 0;
+    sort(es.begin(), es.end());
+    for (auto const& e : es) {
+        ll w = e[0];
+        int u = e[1];
+        if (w * A >= B) continue;
+        ans += w * A;
+        has_next[u] = true;
+    }
+    for (int i = 0; i < N - 1; ++i) {
+        if (has_next[i]) continue;
+        ans += B;
+    }
+    return ans;
+}
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(0); cout.tie(0);
+
+    cin >> N >> A >> B;
+    X.assign(N, 0);
+    for (int i = 0; i < N; ++i) {
+        cin >> X[i];
+    }
+    cout << solve() << endl;
+
+    return 0;
+}