oj.uz

Submission #499321

# Submission time Handle Problem Language Result Execution time Memory
499321 2021-12-28T02:50:10 Z tphuc2908 Tracks in the Snow (BOI13_tracks) C++14
100 / 100
 1673 ms 167168 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] = 1;
    q[1].push(mp(x, y));
    int num = 1, pos = 1;
    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;
}

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 8268 KB Output is correct
2 Correct 1 ms 456 KB Output is correct
3 Correct 1 ms 844 KB Output is correct
4 Correct 12 ms 7616 KB Output is correct
5 Correct 5 ms 4428 KB Output is correct
6 Correct 1 ms 588 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 1484 KB Output is correct
10 Correct 4 ms 3648 KB Output is correct
11 Correct 4 ms 3020 KB Output is correct
12 Correct 7 ms 4556 KB Output is correct
13 Correct 4 ms 4432 KB Output is correct
14 Correct 5 ms 4564 KB Output is correct
15 Correct 17 ms 8164 KB Output is correct
16 Correct 20 ms 8396 KB Output is correct
17 Correct 19 ms 8040 KB Output is correct
18 Correct 13 ms 7708 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 24 ms 46412 KB Output is correct
2 Correct 79 ms 26100 KB Output is correct
3 Correct 396 ms 135968 KB Output is correct
4 Correct 134 ms 54808 KB Output is correct
5 Correct 276 ms 100388 KB Output is correct
6 Correct 1673 ms 167168 KB Output is correct
7 Correct 24 ms 48460 KB Output is correct
8 Correct 22 ms 46364 KB Output is correct
9 Correct 3 ms 920 KB Output is correct
10 Correct 1 ms 596 KB Output is correct
11 Correct 23 ms 47556 KB Output is correct
12 Correct 2 ms 2252 KB Output is correct
13 Correct 79 ms 26200 KB Output is correct
14 Correct 43 ms 17612 KB Output is correct
15 Correct 42 ms 20916 KB Output is correct
16 Correct 30 ms 9744 KB Output is correct
17 Correct 205 ms 52772 KB Output is correct
18 Correct 151 ms 59436 KB Output is correct
19 Correct 139 ms 54876 KB Output is correct
20 Correct 95 ms 46024 KB Output is correct
21 Correct 242 ms 101188 KB Output is correct
22 Correct 274 ms 100360 KB Output is correct
23 Correct 408 ms 83124 KB Output is correct
24 Correct 241 ms 97740 KB Output is correct
25 Correct 708 ms 156960 KB Output is correct
26 Correct 927 ms 135704 KB Output is correct
27 Correct 1353 ms 158696 KB Output is correct
28 Correct 1627 ms 167084 KB Output is correct
29 Correct 1482 ms 165576 KB Output is correct
30 Correct 1401 ms 162124 KB Output is correct
31 Correct 1063 ms 123764 KB Output is correct
32 Correct 1204 ms 157680 KB Output is correct