oj.uz

Submission #499324

# Submission time Handle Problem Language Result Execution time Memory
499324 2021-12-28T02:54:07 Z tphuc2908 Tracks in the Snow (BOI13_tracks) C++14
100 / 100
 1681 ms 151660 KB 
#include<bits/stdc++.h>

using namespace std;
//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,fma")
//#pragma GCC optimization ("unroll-loops")
#define rep(i, x, y) for(int i = x; i <= y; ++i)
#define repi(i,x,y) for(int i = x; i >= y; --i)
#define ci(x) int x; cin>> x
#define TC(t) ci(t); while(t--)
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define cii(x, y) ci(x); ci(y)
#define ciii(x, y, z) ci(x); ci(y); ci(z)
#define mp make_pair
//#define int long long
typedef long long ll;
typedef vector<int> vi;
const int N = 4e3 + 5;
const int mod = 1e9 + 7;
const int mod1 = 1e9 + 9;
const int pi = 31;
const int inf = 1e9 + 5;
const int block = 330;
const int dx[4] = {0, 0, 1, -1};
const int dy[4] = {1, -1, 0, 0};

void readfile(){
    #ifdef ONLINE_JUDGE
    #else
        freopen("text.inp", "r", stdin);
    #endif // ONLINE_JUDGE
//    freopen("248.in", "r", stdin);
//    freopen("248.out", "w", stdout);
}

int n, m;
char a[N][N];

void inp(){
    cin >> n >> m;
    rep(i,1,n)
        rep(j,1,m)
            cin >> a[i][j];
}

queue<pair<int,int> > q[2];
int d[N][N], vis[N][N];

void bfs(int x, int y){
    rep(i,1,n)
        rep(j,1,m)
            d[i][j] = inf;
    d[x][y] = 0;
    q[0].push(mp(x, y));
    int num = 1, pos = 0;
    while(num){
        while(q[pos % 2].empty())
            ++pos;
        auto top = q[pos % 2].front();
        q[pos % 2].pop(), --num;
        if(vis[top.fi][top.se]) continue;
        vis[top.fi][top.se] = 1;
        rep(i,0,3){
            int x = top.fi + dx[i];
            int y = top.se + dy[i];
            if(1 <= x && x <= n && 1 <= y && y <= m && a[x][y]!='.'){
                int cost = (a[x][y] != a[top.fi][top.se]);
                if(d[x][y] > d[top.fi][top.se] + cost){
                    d[x][y] = d[top.fi][top.se] + cost;
                    q[d[x][y] % 2].push(mp(x, y));
                    ++num;
                }
            }
        }
    }
}

void process(){
    bfs(1,1);
    int res = 0;
    rep(i,1,n)
        rep(j,1,m)
            if(d[i][j]!=inf)
                res = max(res, d[i][j]);
    cout << res + 1;
}

int main() {
   // readfile();
    ios_base::sync_with_stdio(0);
    cin.tie(0);
//    TC(t){
        inp();
        process();
//    }
    return 0;
}

Compilation message

tracks.cpp: In function 'void readfile()':
tracks.cpp:33:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |         freopen("text.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 8064 KB Output is correct
2 Correct 0 ms 460 KB Output is correct
3 Correct 1 ms 844 KB Output is correct
4 Correct 13 ms 7568 KB Output is correct
5 Correct 4 ms 4316 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 1 ms 844 KB Output is correct
8 Correct 1 ms 972 KB Output is correct
9 Correct 1 ms 1544 KB Output is correct
10 Correct 4 ms 3660 KB Output is correct
11 Correct 3 ms 3020 KB Output is correct
12 Correct 9 ms 4428 KB Output is correct
13 Correct 5 ms 4380 KB Output is correct
14 Correct 5 ms 4300 KB Output is correct
15 Correct 17 ms 8028 KB Output is correct
16 Correct 23 ms 8068 KB Output is correct
17 Correct 16 ms 7868 KB Output is correct
18 Correct 12 ms 7484 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 46364 KB Output is correct
2 Correct 92 ms 24664 KB Output is correct
3 Correct 382 ms 120336 KB Output is correct
4 Correct 142 ms 51256 KB Output is correct
5 Correct 267 ms 91524 KB Output is correct
6 Correct 1640 ms 151660 KB Output is correct
7 Correct 23 ms 48412 KB Output is correct
8 Correct 22 ms 46284 KB Output is correct
9 Correct 2 ms 844 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 22 ms 47460 KB Output is correct
12 Correct 2 ms 2252 KB Output is correct
13 Correct 79 ms 24572 KB Output is correct
14 Correct 44 ms 16708 KB Output is correct
15 Correct 43 ms 20000 KB Output is correct
16 Correct 30 ms 9080 KB Output is correct
17 Correct 200 ms 48664 KB Output is correct
18 Correct 156 ms 55468 KB Output is correct
19 Correct 143 ms 51148 KB Output is correct
20 Correct 96 ms 42616 KB Output is correct
21 Correct 235 ms 92144 KB Output is correct
22 Correct 264 ms 91500 KB Output is correct
23 Correct 401 ms 75696 KB Output is correct
24 Correct 248 ms 88900 KB Output is correct
25 Correct 726 ms 141368 KB Output is correct
26 Correct 950 ms 123804 KB Output is correct
27 Correct 1441 ms 143228 KB Output is correct
28 Correct 1681 ms 151604 KB Output is correct
29 Correct 1573 ms 149908 KB Output is correct
30 Correct 1399 ms 146388 KB Output is correct
31 Correct 1075 ms 113684 KB Output is correct
32 Correct 1211 ms 142364 KB Output is correct