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
    for(int i=0;i<snake.size()-1;i++){
        snake[i].first=snake[i+1].first;
        snake[i].second=snake[i+1].second;
    }
   switch (dir) {
        case 1:
        snake.back().second++;
        break;
        case 2:
        snake.back().second--;
        break;
        case 3:
        snake.back().first--;
        break;
        case 4:
        snake.back().first++;
        break;
    }
    for(int i=0;i<snake.size()-1;i++){
        if(snake[i].first==snake.back().first&&snake[i].second==snake.back().second){
            return true;
        }
    }
    return false;
}

bool eatSnake(int dir) {
    // TODO: 请实现吃果子生长逻辑
     int x=snake.front().first;
    int y=snake.front().second;
     for(int i=0;i<snake.size()-1;i++){
        snake[i].first=snake[i+1].first;
        snake[i].second=snake[i+1].second;
    }
    switch (dir) {
        case 1:
        snake.back().second++;
        break;
        case 2:
        snake.back().second--;
        break;
        case 3:
        snake.back().first--;
        break;
        case 4:
        snake.back().first++;
        break;
    }
   
    snake.insert(snake.begin(),{x,y});
    for(int i=0;i<snake.size()-1;i++){
        if(snake[i].first==snake.back().first&&snake[i].second==snake.back().second){
            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;
}

不知道为什么放在哈希表这一块