P1063 [NOIP2006 提高组] 能量项链

R73362890

Luogu/P1063/P1063.cpp

@@ -0,0 +1,35 @@
+#include <iostream>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 105 << 1;
+
+int n, a[N], f[N][N], ans;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+
+    cin >> n;
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+        a[n + i] = a[i];
+    }
+
+    for (int len = 2; len <= n; len++) {
+        for (int l = 1, r = len; r <= n << 1; l++, r++) {
+            for (int k = l; k < r; k++) {
+                f[l][r] = std::max(f[l][r], f[l][k] + f[k + 1][r] + a[l] * a[k + 1] * a[r + 1]);
+            }
+        }
+    }
+
+    for (int i = 1; i <= n; i++) {
+        ans = std::max(ans, f[i][n + i - 1]);
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}