#1806. 【2017.3 长乐省选集训 Day7 T2】序列游戏

https://sjzezoj.com/submission/66126

S2OJ/1806/1806.cpp

@@ -0,0 +1,81 @@
+#include <iostream>
+#include <algorithm>
+#include <cstring>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 155;
+
+int n, v[N], a[N];
+int f[N][N], g[N][N], h[N][N][N];
+std::vector<int> nums, pos[N << 1];
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> v[i];
+    }
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+
+        nums.emplace_back(a[i]);
+        nums.emplace_back(a[i] + 1);
+    }
+
+    std::sort(nums.begin(), nums.end());
+    nums.erase(std::unique(nums.begin(), nums.end()), nums.end());
+
+    for (int i = 1; i <= n; i++) {
+        a[i] = std::lower_bound(nums.begin(), nums.end(), a[i]) - nums.begin() + 1;
+        pos[a[i]].emplace_back(i);
+    }
+
+    memset(f, 0xcf, sizeof(f));
+    memset(g, 0xcf, sizeof(g));
+    memset(h, 0xcf, sizeof(h));
+
+    for (int i = 1; i <= n; i++) {
+        f[i][i] = std::max(0, v[1]);
+        g[i][i] = v[1];
+        g[i][i - 1] = h[i][i][1] = 0;
+    }
+
+    for (int len = 2; len <= n; len++) {
+        for (int l = 1, r = len; r <= n; l++, r++) {
+            for (int k = 2; k <= len; k++) {
+                for (int p : pos[a[l] + 1]) {
+                    if (l <= p && p <= r) {
+                        h[l][r][k] = std::max(h[l][r][k], h[p][r][k - 1] + g[l + 1][p - 1]);
+                    }
+                }
+
+                for (int p : pos[a[r] + 1]) {
+                    if (l <= p && p <= r) {
+                        h[l][r][k] = std::max(h[l][r][k], h[l][p][k - 1] + g[p + 1][r - 1]);
+                    }
+                }
+
+                g[l][r] = std::max(g[l][r], h[l][r][k] + v[k]);
+            }
+
+            for (int k = l; k < r; k++) {
+                f[l][r] = std::max(f[l][r], f[l][k] + f[k + 1][r]);
+                g[l][r] = std::max(g[l][r], g[l][k] + g[k + 1][r]);
+            }
+
+            f[l][r] = std::max(f[l][r], g[l][r]);
+        }
+    }
+
+    cout << f[1][n] << endl;
+
+    return 0;
+}