#1512. 【CSP七连测Day1】高爸

https://sjzezoj.com/submission/56204

S2OJ/1512/1512.cpp

@@ -0,0 +1,72 @@
+#include <iostream>
+#include <algorithm>
+#include <set>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int n, a, b, c, d_up = 0, d_down = 0;
+    long long ans = 0;
+
+    cin >> n >> a >> b;
+
+    std::vector<int> nums, x(n);
+
+    for (int& x : x) {
+        cin >> x;
+    }
+
+    std::set<int> s1;
+    std::multiset<int> s2;
+
+    for (int i = 0; i < n; i++) {
+        s1.insert(x[i]);
+        s2.insert(x[i]);
+
+        if (i == 0) {
+            c = x[i];
+        } else {  // i > 0
+            if (c > x[i]) {
+                ans += static_cast<long long>(a) * (c - x[i]);
+                d_down++;
+            } else if (c < x[i]) {
+                ans += static_cast<long long>(b) * (x[i] - c);
+                d_up++;
+            }
+
+            if (c != *s1.begin()) {
+                auto it = --s1.lower_bound(c);
+                int d = (d_up + s2.count(c)) * b - d_down * a;
+
+                if (d < 0 && c != *it) {
+                    ans += static_cast<long long>(d) * (c - *it);
+                    d_up += s2.count(c);
+                    d_down -= s2.count(*it);
+                    c = *it;
+                }
+            }
+
+            if (c != *s1.rbegin()) {
+                auto it = s1.upper_bound(c);
+                int d = (d_down + s2.count(c)) * a - d_up * b;
+
+                if (d < 0 && c != *it) {
+                    ans += static_cast<long long>(d) * (*it - c);
+                    d_up -= s2.count(*it);
+                    d_down += s2.count(c);
+                    c = *it;
+                }
+            }
+        }
+
+        cout << ans << endl;
+    }
+
+    return 0;
+}