题解 | 贪吃蛇游戏

#include <bits/stdc++.h>
using namespace std;
using ll = long long;

deque<pair<int,int>> snake;

bool moveSnake(int dir) {
    // TODO: 请实现移动逻辑
    snake.pop_front();
    snake.push_back(snake.back());
    switch (dir) {
    case 1:
    snake.back().second+=1;
    break;
    case 2:
    snake.back().second-=1;
    break;
    case 3:
    snake.back().first-=1;
    break;
    case 4:
    snake.back().first+=1;
    break;
    }
    auto it=find(snake.begin(),prev(snake.end()),snake.back());
    if(it!=prev(snake.end()))
    return true;
    return false;
}

bool eatSnake(int dir) {
    // TODO: 请实现吃果子生长逻辑
    snake.push_back(snake.back());
    switch (dir) {
    case 1:
    snake.back().second+=1;
    break;
    case 2:
    snake.back().second-=1;
    break;
    case 3:
    snake.back().first-=1;
    break;
    case 4:
    snake.back().first+=1;
    break;
    }
    auto it=find(snake.begin(),prev(snake.end()),snake.back());
    if(it!=prev(snake.end()))
    return true;
    return false;
}



int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, q;
    cin >> n >> q;
    snake.clear();
    for (int i = 0; i < n; i++) {
        int x, y;
        cin >> x >> y;
        snake.emplace_back(x, y);
    }
    for (int i = 0; i < q; i++) {
        int op, dir;
        cin >> op >> dir;
        bool collision = (op == 1 ? moveSnake(dir) : eatSnake(dir));
        if (collision) {
            cout << -1 << '\n';
            return 0;
        } else {
            for (auto it = snake.rbegin(); it != snake.rend(); ++it) {
                cout << it->first << ' ' << it->second << '\n';
            }
        }
    }
    return 0;
}