题解 | #【模板】01背包（方案输出）#

没想到竟然过了

代码实现

#include <bits/stdc++.h>

#define x first
#define y second

using namespace std;

typedef long long LL;
typedef pair<int, int> PII;

const int N = 1e4 + 10, MOD = 998244353;
const LL INF = 1e18;

int n, m;
LL v[N], w[N];

void solve() {
    cin >> n >> m;
    for (int i = 1; i <= n; ++i) cin >> v[i] >> w[i];

    vector<vector<LL>> f(n + 1, vector<LL>(m + 1));

    for (int i = 1; i <= n; ++i) {
        for (int j = 0; j <= m; ++j) {
            f[i][j] = f[i - 1][j];
            if (j >= v[i]) f[i][j] = max(f[i][j], f[i - 1][j - v[i]] + w[i]);
        }
    }

    vector<int> ans;
    int j = m;
    for (int i = n; i >= 1; --i) {
        if (j >= v[i] && f[i - 1][j - v[i]] + w[i] == f[i][j]) {
            ans.push_back(i);
            j -= v[i];
        }
    }

    cout << ans.size() << '\n';
    for (int i : ans) cout << i << ' ';
    cout << '\n';
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    int T;
    cin >> T;
    while (T--) solve();

    return 0;
}