#1170898 (C++23) No.3585 Make Ends Meet (Easy)

• 問題: No.3585 Make Ends Meet (Easy)
• ユーザー: Iroha_3856
• 提出日時: 2026-07-10 22:04:59
• 言語: C++23 (gcc 15.2.0 + boost 1.90.0)
• 結果: WA
• 実行時間: -
• コード長: 3,648 bytes
• コンパイル時間: 4,254 ms
• コンパイル使用メモリ: 385,292 KB
• 実行使用メモリ: 12,032 KB
• 最終ジャッジ日時: 2026-07-10 22:05:12
• 合計ジャッジ時間: 6,522 ms
• ジャッジサーバーID （参考情報）: judge3_0 / judge2_0

ファイルパターン	結果
sample	AC * 2
other	AC * 39 WA * 9

ソースコード

#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using mint = atcoder::modint998244353;

#define rep(i, l, r) for (int i = (l); i < (r); i++)
#define ll long long
#define all(x) (x).begin(), (x).end()
#define siz(x) (int)x.size()

#define debug(x) cout << #x << " : " << endl; for (auto u : x) cout << u << " "; cout << endl

template<class T> bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<class T> bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }

const int inf = 1e9;
const ll INF = 4e18;

template<class T> using spq = priority_queue<T, vector<T>, greater<T>>;

vector<int> di = {1, 0, -1, 0}, dj = {0, 1, 0, -1};

int main() {
    int N, M, K; cin >> N >> M >> K;
    int R = N * (N - 1) / 2 - M;

    if (R < N - 1) {
        cout << "No\n";
        return 0;
    }

    // vector<int> A(K + 1, 1);

    // auto score = [&](vector<int> X) -> int {
    //     int ret = 0;
    //     rep(i, 0, K) ret += A[i] * A[i + 1];
    //     rep(i, 0, K + 1) ret += A[i] * (A[i] - 1) / 2;
    //     return ret;
    // };

    // rep(_, 0, N - K - 1) {
    //     int amx = -1, mx = -1;
    //     rep(j, 1, K + 1) {
    //         A[j]++;
    //         if (chmax(mx, score(A))) amx = j;
    //         A[j]--;
    //     }
    //     A[amx]++;
    // }

    //謎の貪欲をしなくてもdpできますやん！！

    //i, used, last
    vector dp(K + 1, vector(N + 1, vector<int>(N + 1, -1)));
    vector from(K + 1, vector(N + 1, vector<int>(N + 1, -1)));
    dp[0][1][1] = 0;
    
    rep(i, 0, K) {
        rep(j, 0, N + 1) rep(k, 0, N + 1) {
            if (dp[i][j][k] == -1) continue;
            rep(l, 1, N + 1) {
                if (j + l <= N) {
                    if (chmax(dp[i + 1][j + l][l], dp[i][j][k] + k * l + l * (l - 1) / 2)) {
                        from[i + 1][j + l][l] = k;
                    }
                }
            }
        }
    }

    int ci = K, cj = 0, ck = 0;
    rep(j, 0, N + 1) rep(k, 0, N + 1) {
        if (dp[K][j][k] > dp[ci][cj][ck]) {
            cj = j; ck = k;
        }
    }

    int sc = dp[K][cj][ck];

    vector<int> A;
    while(true) {
        A.push_back(ck);
        int memo = from[ci][cj][ck];
        ci--;
        cj -= ck;
        ck = memo;
        if (ci == -1) break;
    }

    reverse(all(A));

    if (R <= sc) {
        cout << "Yes\n";

        vector<vector<int>> V(K + 1);
        int c = 0;
        rep(i, 0, K + 1) {
            rep(_, 0, A[i]) V[i].push_back(c++);
        }

        vector<vector<bool>> choose(N, vector<bool>(N, false));

        vector<pair<int, int>> choosable;
        rep(i, 0, K) {
            rep(j, 0, A[i]) rep(k, 0, A[i + 1]) {
                if (j == 0) {
                    choose[V[i][j]][V[i + 1][k]] = true;
                }
                else {
                    choosable.push_back({V[i][j], V[i + 1][k]});
                }
            }
        }
        rep(i, 0, K + 1) {
            rep(j, 0, A[i]) rep(k, j + 1, A[i]) {
                choosable.push_back({V[i][j], V[i][k]});
            }
        }

        // cout << "choosable : " << "\n";
        // for (auto[u, v] : choosable) {
        //     cout << u << " " << v << "\n";
        // }
        // cout << "====" << endl;

        int chosen = N - 1;

        // assert(siz(choosable) >= R - chosen);s
        rep(i, 0, R - chosen) {
            auto[u, v] = choosable[i];
            choose[u][v] = true;
        }

        rep(i, 0, N) rep(j, i + 1, N) {
            if (not choose[i][j]) cout << i + 1 << " " << j + 1 << "\n";
        }
    }
    else {
        cout << "No\n";
    }
}