oj.uz

Submission #759272

# Submission time Handle Problem Language Result Execution time Memory
759272 2023-06-16T02:26:36 Z fanwen Tracks in the Snow (BOI13_tracks) C++17
100 / 100
 573 ms 138908 KB 
/**
 *      author : pham van sam 
 *      created : 16 June 2023 (Friday)
 **/

#include <bits/stdc++.h>

using namespace std;
using namespace chrono;

#define MASK(x) (1LL << (x))
#define BIT(x, i) (((x) >> (i)) & 1)
#define ALL(x) (x).begin(), (x).end()
#define REP(i, n) for (int i = 0, _n = n; i < _n; ++i)
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; --i)
#define FORE(it, s) for (__typeof(s.begin()) it = (s).begin(); it != (s).end(); ++it)

template <typename U, typename V> bool maximize(U &A, const V &B) { return (A < B) ? (A = B, true) : false; }
template <typename U, typename V> bool minimize(U &A, const V &B) { return (A > B) ? (A = B, true) : false; }

const int MAXN = 4e3 + 5;
const int dir[] = {1, -1, 0, 0, 0, 0, 1, -1};

int N, M, dp[MAXN][MAXN];
char a[MAXN][MAXN];

void process(void) {
    cin >> N >> M;
    FOR(i, 1, N) FOR(j, 1, M) cin >> a[i][j];
    deque <pair <int, int>> q;
    memset(dp, 0x3f, sizeof dp);
    q.emplace_front(1, 1); dp[1][1] = 1;
    while(!q.empty()) {
        auto [u, v] = q.front(); q.pop_front();
        REP(i, 4) {
            int x = u + dir[i];
            int y = v + dir[i + 4];
            if(x < 1 || x > N || y < 1 || y > M) continue;
            if(a[x][y] == '.') continue;
            int cost = (a[x][y] != a[u][v] ? 1 : 0);
            if(minimize(dp[x][y], dp[u][v] + cost)) {
                if(!cost) q.emplace_front(x, y);
                else q.emplace_back(x, y);
            }
        }
    }
    int ans = 0;
    FOR(i, 1, N) FOR(j, 1, M) if(a[i][j] != '.') {
        maximize(ans, dp[i][j]);
    }
    cout << ans;
}

signed main() {

    #define TASK "tracks"
    if(fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }

    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    auto start_time = steady_clock::now();
    int test = 1;
    // cin >> test;
    for (int i = 1; i <= test; ++i) {
        process();
        // cout << '\n';
    }

    auto end_time = steady_clock::now();

    cerr << "\nExecution time : " << duration_cast<milliseconds> (end_time - start_time).count() << "[ms]" << endl;

    return (0 ^ 0);
}

Compilation message

tracks.cpp: In function 'int main()':
tracks.cpp:59:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
tracks.cpp:60:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 65312 KB Output is correct
2 Correct 21 ms 63056 KB Output is correct
3 Correct 24 ms 63276 KB Output is correct
4 Correct 31 ms 65304 KB Output is correct
5 Correct 24 ms 64308 KB Output is correct
6 Correct 21 ms 63156 KB Output is correct
7 Correct 21 ms 63316 KB Output is correct
8 Correct 23 ms 63324 KB Output is correct
9 Correct 21 ms 63384 KB Output is correct
10 Correct 22 ms 64084 KB Output is correct
11 Correct 22 ms 63936 KB Output is correct
12 Correct 26 ms 64280 KB Output is correct
13 Correct 24 ms 64200 KB Output is correct
14 Correct 24 ms 64312 KB Output is correct
15 Correct 32 ms 65236 KB Output is correct
16 Correct 37 ms 65332 KB Output is correct
17 Correct 29 ms 65220 KB Output is correct
18 Correct 28 ms 65336 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 78064 KB Output is correct
2 Correct 62 ms 69536 KB Output is correct
3 Correct 263 ms 94404 KB Output is correct
4 Correct 94 ms 74148 KB Output is correct
5 Correct 156 ms 83640 KB Output is correct
6 Correct 573 ms 108048 KB Output is correct
7 Correct 26 ms 78768 KB Output is correct
8 Correct 26 ms 78000 KB Output is correct
9 Correct 22 ms 63128 KB Output is correct
10 Correct 24 ms 63108 KB Output is correct
11 Correct 32 ms 78412 KB Output is correct
12 Correct 21 ms 63696 KB Output is correct
13 Correct 60 ms 69536 KB Output is correct
14 Correct 44 ms 67564 KB Output is correct
15 Correct 46 ms 68036 KB Output is correct
16 Correct 41 ms 65228 KB Output is correct
17 Correct 120 ms 74984 KB Output is correct
18 Correct 90 ms 74752 KB Output is correct
19 Correct 90 ms 74148 KB Output is correct
20 Correct 81 ms 73328 KB Output is correct
21 Correct 176 ms 84324 KB Output is correct
22 Correct 157 ms 83644 KB Output is correct
23 Correct 205 ms 80460 KB Output is correct
24 Correct 166 ms 84200 KB Output is correct
25 Correct 390 ms 94372 KB Output is correct
26 Correct 321 ms 138908 KB Output is correct
27 Correct 407 ms 120956 KB Output is correct
28 Correct 569 ms 108008 KB Output is correct
29 Correct 551 ms 106388 KB Output is correct
30 Correct 510 ms 111528 KB Output is correct
31 Correct 495 ms 86204 KB Output is correct
32 Correct 393 ms 109708 KB Output is correct