oj.uz

Submission #499327

# Submission time Handle Problem Language Result Execution time Memory
499327 2021-12-28T03:00:26 Z tphuc2908 Tracks in the Snow (BOI13_tracks) C++14
100 / 100
 1639 ms 151628 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].empty())
            pos = (pos + 1) % 2;
        auto top = q[pos].front();
        q[pos].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 8140 KB Output is correct
2 Correct 1 ms 460 KB Output is correct
3 Correct 1 ms 844 KB Output is correct
4 Correct 12 ms 7552 KB Output is correct
5 Correct 5 ms 4300 KB Output is correct
6 Correct 0 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 1484 KB Output is correct
10 Correct 4 ms 3660 KB Output is correct
11 Correct 3 ms 3020 KB Output is correct
12 Correct 7 ms 4516 KB Output is correct
13 Correct 5 ms 4300 KB Output is correct
14 Correct 4 ms 4300 KB Output is correct
15 Correct 17 ms 8012 KB Output is correct
16 Correct 19 ms 8080 KB Output is correct
17 Correct 14 ms 7756 KB Output is correct
18 Correct 12 ms 7500 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 23 ms 46332 KB Output is correct
2 Correct 77 ms 24688 KB Output is correct
3 Correct 382 ms 120344 KB Output is correct
4 Correct 129 ms 51152 KB Output is correct
5 Correct 274 ms 91608 KB Output is correct
6 Correct 1639 ms 151628 KB Output is correct
7 Correct 24 ms 48460 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 23 ms 47540 KB Output is correct
12 Correct 2 ms 2252 KB Output is correct
13 Correct 78 ms 24604 KB Output is correct
14 Correct 43 ms 16632 KB Output is correct
15 Correct 40 ms 19972 KB Output is correct
16 Correct 30 ms 9156 KB Output is correct
17 Correct 203 ms 48700 KB Output is correct
18 Correct 160 ms 55416 KB Output is correct
19 Correct 133 ms 51140 KB Output is correct
20 Correct 94 ms 42632 KB Output is correct
21 Correct 236 ms 92040 KB Output is correct
22 Correct 275 ms 91588 KB Output is correct
23 Correct 391 ms 75372 KB Output is correct
24 Correct 237 ms 88904 KB Output is correct
25 Correct 700 ms 141380 KB Output is correct
26 Correct 1049 ms 123940 KB Output is correct
27 Correct 1266 ms 143148 KB Output is correct
28 Correct 1626 ms 151596 KB Output is correct
29 Correct 1567 ms 149916 KB Output is correct
30 Correct 1410 ms 146320 KB Output is correct
31 Correct 1079 ms 113676 KB Output is correct
32 Correct 1149 ms 142188 KB Output is correct