暴力枚举大法，再加个广搜，包ac的

代码放了

#include <iostream>
#include <vector>
#include <queue>
#include <tuple>
#include <algorithm>
using namespace std;
const int MAX_N = 5000;
const int INF = 1e9;
int n, M, K;
vector<pair<int, int>> enemies;
vector<tuple<int, int, int>> zhxTroops;
int dist[MAX_N][MAX_N];
bool isEnemy[MAX_N][MAX_N];
int dx[4] = {0, 0, 1, -1};
int dy[4] = {1, -1, 0, 0};
int main() {
    cin >> n >> M >> K;
    enemies.resize(M);
    zhxTroops.resize(K);
    for (int i = 0; i < M; ++i) {
        int x, y;
        cin >> x >> y;
        enemies[i] = {x - 1, y - 1}; 
        isEnemy[x - 1][y - 1] = true;
    }

    for (int i = 0; i < K; ++i) {
        int sx, sy, t;
        cin >> sx >> sy >> t;
        zhxTroops[i] = {sx - 1, sy - 1, t}; 
    }
    for (int i = 0; i < n; ++i) {
        fill(dist[i], dist[i] + n, INF);
    }
    queue<tuple<int, int, int>> q;
    for (const auto& troop : zhxTroops) {
        int sx, sy, t;
        tie(sx, sy, t) = troop;
        q.push({sx, sy, t});
        dist[sx][sy] = min(dist[sx][sy], t);
    }
    while (!q.empty()) {
        int x, y, t;
        tie(x, y, t) = q.front();
        q.pop();
        for (int i = 0; i < 4; ++i) {
            int nx = x + dx[i];
            int ny = y + dy[i];
            if (nx >= 0 && ny >= 0 && nx < n && ny < n && dist[nx][ny] > t + 1) {
                dist[nx][ny] = t + 1;
                q.push({nx, ny, t + 1});
            }
        }
    }
    int maxTime = 0;
    for (const auto& enemy : enemies) {
        int x = enemy.first;
        int y = enemy.second;
        maxTime = max(maxTime, dist[x][y]);
    }
    cout << maxTime << endl;
    return 0;
}