P4138 [JOISC2014] 挂饰

https://www.luogu.com.cn/record/94138309

Luogu/P4138/P4138.cpp

@@ -0,0 +1,43 @@
+#include <iostream>
+#include <algorithm>
+#include <cstring>
+#include <functional>
+#include <utility>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 2005;
+
+int n, f[N][N], ans;
+std::pair<int, int> a[N];
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i].first >> a[i].second;
+    }
+
+    std::sort(a + 1, a + 1 + n, std::greater<>());
+    memset(f, 0xc0, sizeof(f));
+
+    f[0][1] = 0;
+    for (int i = 1; i <= n; i++) {
+        for (int j = 0; j <= n; j++) {
+            f[i][j] = std::max(f[i - 1][j], f[i - 1][std::max(j - a[i].first, 0) + 1] + a[i].second);
+        }
+    }
+
+    for (int i = 0; i <= n; i++) {
+        ans = std::max(ans, f[n][i]);
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}