Submission #715705

#	Time	Username	Problem	Language	Result	Execution time	Memory
715705		hamidh100	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	928 ms	962152 KiB

tracks

/* In the name of God */

#include <iostream>
#include <iomanip>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string>
#include <string.h>
#include <algorithm>
#include <bitset>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <list>
#include <map>
#include <numeric>
#include <limits>
#include <limits.h>
#include <unordered_map>
#include <unordered_set>
#include <chrono>
#include <random>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef map<int, int> MPII;
typedef vector<int> VI;
typedef vector<ll> VL;
#define PB push_back
#define POP pop_back
#define MP make_pair
#define all(a) (a).begin(), (a).end()
#define endl '\n'
#define dbg(x) cerr << '[' << #x << ": " << x << "]\n"
#define dbg2(x, y) cerr << '[' << #x << ": " << x << ", " << #y << ": " << y << "]\n"
#define Yes cout << "Yes\n"
#define YES cout << "YES\n"
#define No cout << "No\n"
#define NO cout << "NO\n"

const ll INF = (ll)2e18 + 1386;
const ld eps = 0.000000000000001;
const int MOD = 1e9 + 7;

inline int mod_(int a){ int res = a + MOD; return (res >= MOD? res - MOD : res); }
inline int mod_add(int a, int b){ int res = a + b; return (res >= MOD? res - MOD : res); }
inline int mod_neg(int a, int b){ int res = (abs(a - b) < MOD? a - b : (a - b) % MOD); return (res < 0? res + MOD : res); }
inline int mod_mlt(int a, int b){ return (1ll * a * b % MOD); }
inline string intToString(ll a){ char x[100]; sprintf(x, "%lld", a); string s = x; return s; }
inline ll stringToInt(string s){ ll res; char x[100]; strcpy(x, s.c_str()); sscanf(x, "%lld", &res); return res; }
inline void fileIO(string i, string o){ freopen(i.c_str(), "r", stdin); freopen(o.c_str(), "w", stdout); }

const int MAXN = 4000;

int cmp, n, m;
VI nxt;
bitset<MAXN * MAXN> mark, a;

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

int get_id(int x, int y){
    return (x * m + y);
}

PII get_pos(int id){
    return MP(id / m, id % m);
}

void dfs(int x, int y){
    int tmpn = get_id(x, y);
    mark[tmpn] = 1;
    for (int i = 0; i < 4; i++){
        int xx = x + dx[i], yy = y + dy[i];
        int tmp = get_id(xx, yy);
        if (xx < n && xx >= 0 && yy >= 0 && yy < m && !mark[tmp]){
            if (a[tmp] ^ 1 == a[tmpn]){
                nxt.PB(tmp);
            }
            else if (a[tmp] == a[tmpn]) dfs(xx, yy);
        }
    }
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> m;
    for (int i = 0; i < n; i++){
        for (int j = 0; j < m; j++){
            int id = get_id(i, j);
            char ch; cin >> ch;
            if (ch == 'F') a[id] = 0;
            else if (ch == 'R') a[id] = 1;
            else mark[id] = 1;
        }
    }
    nxt.PB(0);
    int lst = 0;
    while (true){
        int tmp = nxt.size();
        if (lst >= tmp) break;
        cmp++;
        for (int i = lst; i < tmp; i++){
            int x = get_pos(nxt[i]).first, y = get_pos(nxt[i]).second;
            if (!mark[nxt[i]]) dfs(x, y);
        }
        lst = tmp;
    }
    cout << cmp;
    return 0;
}

Compilation message (stderr)

tracks.cpp: In function 'void dfs(int, int)':
tracks.cpp:83:28: warning: suggest parentheses around comparison in operand of '^' [-Wparentheses]
   83 |             if (a[tmp] ^ 1 == a[tmpn]){
      |                          ~~^~~~~~~~~~

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70