P1091 [NOIP2004 提高组] 合唱队形

R72624461

Luogu/P1091/P1091.cpp

@@ -0,0 +1,40 @@
+#include <cstring>
+#include <iostream>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 105;
+
+int n, a[N], f[N], g[N], ans;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+
+    cin >> n;
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+    }
+
+    for (int i = 1; i <= n; i++) {
+        f[i] = 1;
+        for (int j = 1; j < i; j++) {
+            if (a[i] > a[j]) f[i] = std::max(f[i], f[j] + 1);
+        }
+    }
+    for (int i = n; i >= 1; i--) {
+        g[i] = 1;
+        for (int j = n; j > i; j--) {
+            if (a[i] > a[j]) g[i] = std::max(g[i], g[j] + 1);
+        }
+    }
+
+    for (int i = 1; i <= n; i++) {
+        ans = std::max(ans, f[i] + g[i] - 1);
+    }
+
+    cout << n - ans << endl;
+
+    return 0;
+}