P1441 砝码称重

https://www.luogu.com.cn/record/78343607

Luogu/P1441/P1441.cpp

@@ -0,0 +1,40 @@
+#include <iostream>
+#include <bitset>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 20;
+
+int n, m, a[N], ans;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> m;
+
+    for (int i = 0; i < n; i++) {
+        cin >> a[i];
+    }
+
+    for (int i = 0; i < 1 << n; i++) {
+        if (__builtin_popcount(i) == n - m) {
+            std::bitset<2005> s;
+            s[0] = 1;
+
+            for (int j = 0; j < n; j++) {
+                if (i & (1 << j)) {
+                    s |= s << a[j];
+                }
+            }
+
+            ans = std::max(ans, (int)s.count());
+        }
+    }
+
+    cout << ans - 1 << endl;
+
+    return 0;
+}