#1550. 【2022.09.11 NOIP 模拟】假冒泡排序

https://sjzezoj.com/submission/56272

S2OJ/1550/1550.cpp

@@ -0,0 +1,38 @@
+#include <iostream>
+#include <algorithm>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5;
+
+int n, a[N], c[N], p, ans;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    bool flag = n >= 3;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+
+        if (a[i] == n) p = i;
+    }
+
+    flag &= a[1] == n - 1 && a[n] == n;
+
+    for (int i = 1; i < p; i++) {
+        if (a[i] > a[i + 1]) {
+            ans++;
+            std::swap(a[i], a[i + 1]);
+        }
+    }
+
+    cout << static_cast<long long>(n) * (n - 1) + ans - flag << endl;
+
+    return 0;
+}