ソースコード
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
const int inf = 1012345678;
int main() {
int N, K, B;
cin >> N >> K >> B;
vector<int> A(N);
for (int i = 0; i < N; ++i) {
cin >> A[i];
}
vector<int> s(1 << N);
for (int i = 0; i < 1 << N; ++i) {
for (int j = 0; j < N; ++j) {
if ((i >> j) & 1) s[i] += A[j];
}
s[i] = (s[i] + B - 1) / B;
}
vector<int> dp(1 << N, inf);
dp[0] = 0;
for (int i = 0; i <= N; ++i) {
for (int j = (1 << N) - 1; j >= 0; --j) {
dp[j] = inf;
for (int k = j; k > 0; k = (k - 1) & j) {
dp[j] = min(dp[j], dp[j - k] + s[k]);
}
}
if (dp[(1 << N) - 1] > K) {
cout << N - i << '\n';
break;
}
}
return 0;
}