PTA L2-047 锦标赛

题目

解析

把每一场比赛看作满二叉树的一个节点，父节点递归遍历子节点的结果，进行试填。

代码

#include <bits/stdc++.h>

using i64 = long long;

struct Node {
    int win, lose;
};

void solve() {
    int k;
    std::cin >> k;

    int siz = (1 << k);
    std::vector<Node> tree(siz);
    for (int r = k; r > 0; r--) {
        int n = 1 << (r - 1);
        int s = n;
        while (n--) {
            std::cin >> tree[s++].lose;
        }
    }

    std::cin >> tree[1].win;
    if (tree[1].win < tree[1].lose) {
        std::cout << "No Solution\n";
    } else {
        std::function<bool(int, int)> dfs = [&] (int u, int siz) -> bool {
            if (u * 2 >= siz) {
                return true;
            }
            int l = u * 2, r = u * 2 + 1;
            int faw = tree[u].win, fal = tree[u].lose;
            if (faw > tree[l].lose && fal > tree[r].lose) {
                tree[l].win = faw;
                tree[r].win = fal;
                if (dfs(l, siz) && dfs(r, siz)) {
                    return true;
                }
                tree[l].win = tree[r].win = 0;
            }
            if (faw > tree[r].lose && fal > tree[l].lose) {
                tree[r].win = faw;
                tree[l].win = fal;
                if (dfs(l, siz) && dfs(r, siz)) {
                    return true;
                }
            }
            return false;
        };
        if (dfs(1, siz)) {
            for (int i = (1 << (k - 1)); i < siz; i++) {
                std::cout << tree[i].win << " " << tree[i].lose;
                if (i != siz - 1) std::cout << " ";
            }
        } else {
            std::cout << "No Solution\n";
        }
    }

    
}

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr); 

    int t = 1;
    // std::cin >> t;

    for (int i = 1; i <= t; i++) {
        // std::cout << "Case " << i << ": ";
        solve();
    }

    return 0;
}