#152. 【2020.12.2 NOIP模拟赛 T1】最小得分和(mark)

https://sjzezoj.com/submission/43987

S2OJ/152/152.cpp

@@ -0,0 +1,50 @@
+#pragma GCC optimize("Ofast")
+
+#include <bits/stdc++.h>
+
+using namespace std;
+
+long long n, k, a[1000005], sum, cnt, pos, ans, num, res;
+
+bool check(int x);
+
+int main() {
+    cin >> n >> k;
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+    }
+    sort(a + 1, a + n + 1);
+    int l = 1;
+    int r = a[n] - a[1];
+    while (l <= r) {
+        int mid = l + r >> 1;
+        if (check(mid)) {
+            r = mid - 1;
+            num = cnt;
+            pos = mid;
+            ans = res;
+        } else {
+            l = mid + 1;
+        }
+    }
+    cout << ans - (num - k) * pos << endl;
+    return 0;
+}
+
+bool check(int x) {
+    cnt = 0;
+    res = 0;
+    sum = 0;
+    queue<int> q;
+    for (int i = 1; i <= n; i++) {
+        while (!q.empty() && a[i] - a[q.front()] > x) {
+            sum -= a[q.front()];
+            q.pop();
+        }
+        cnt += q.size();
+        res += q.size() * a[i] - sum;
+        q.push(i);
+        sum += a[i];
+    }
+    return cnt >= k;
+}