Endgame.cpp

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

const int MAX_N = 1001;
const int dx[] = {0, 0, 1, -1};
const int dy[] = {1, -1, 0, 0};

int n, m, ans = 0, d = 0;
char table[MAX_N][MAX_N];
queue<tuple<int, int, int>> q;

void bfs()
{
    while (!q.empty())
    {
        auto [x, y, s] = q.front(); // C++17: structured binding declaration
        q.pop();
        if (x < 0 || n <= x || y < 0 || m <= y)
            continue;
        if (table[x][y] == 'C')
            continue;
        if (table[x][y] == 'T')
        {
            ans = max(ans, s);
            d--;
        }
        table[x][y] = 'C';
        for (int i = 0; i < 4; i++)
            q.push({x + dx[i], y + dy[i], s + 1});
    }
}
int main()
{
    cin >> n >> m;
    for (int i = 0; i < n; i++)
        scanf("%s", table[i]);
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < m; j++)
        {
            if (table[i][j] == 'I')
                q.push({i, j, 0});
            else if (table[i][j] == 'T')
                d++;
        }
    }
    bfs();
    printf("%d\n", d != 0 ? -1 : ans);
    return 0;
}