oj.uz

Submission #59164

# Submission time Handle Problem Language Result Execution time Memory
59164 2018-07-20T21:37:36 Z Benq Tracks in the Snow (BOI13_tracks) C++14
100 / 100
 1309 ms 109468 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 4000*4000;

int H,W, dist[4000][4000];
bool done[4000][4000];
string g[4000];
int xd[4] = {0,1,0,-1}, yd[4] = {1,0,-1,0};

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> H >> W;
    F0R(i,H) cin >> g[i];
    
    F0R(i,H) F0R(j,W) dist[i][j] = MOD;
    
    deque<int> q; dist[0][0] = 0; q.pb(0);
    int ans = 0;
    while (sz(q)) {
        int x = q.front(); q.pop_front();
        int y = x%W; x /= W;
        if (done[x][y]) continue;
        done[x][y] = 1;
        ans = max(ans,dist[x][y]);
        F0R(i,4) {
            int X = x+xd[i], Y = y+yd[i];
            if (X < 0 || X >= H || Y < 0 || Y >= W) continue;
            if (g[X][Y] == '.') continue;
            if (g[X][Y] == g[x][y]) {
                if (dist[X][Y] > dist[x][y]) {
                    dist[X][Y] = dist[x][y];
                    q.push_front(W*X+Y);
                }
            } else {
                if (dist[X][Y] > dist[x][y]+1) {
                    dist[X][Y] = dist[x][y]+1;
                    q.pb(W*X+Y);
                }
            }
        }
    }
    cout << ans+1;
}

/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 5496 KB Output is correct
2 Correct 2 ms 5496 KB Output is correct
3 Correct 3 ms 5496 KB Output is correct
4 Correct 17 ms 5496 KB Output is correct
5 Correct 6 ms 5496 KB Output is correct
6 Correct 3 ms 5496 KB Output is correct
7 Correct 4 ms 5496 KB Output is correct
8 Correct 4 ms 5496 KB Output is correct
9 Correct 4 ms 5496 KB Output is correct
10 Correct 7 ms 5496 KB Output is correct
11 Correct 8 ms 5496 KB Output is correct
12 Correct 11 ms 5496 KB Output is correct
13 Correct 7 ms 5496 KB Output is correct
14 Correct 7 ms 5496 KB Output is correct
15 Correct 21 ms 5952 KB Output is correct
16 Correct 25 ms 5952 KB Output is correct
17 Correct 15 ms 5952 KB Output is correct
18 Correct 15 ms 5952 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 30 ms 31084 KB Output is correct
2 Correct 69 ms 31084 KB Output is correct
3 Correct 357 ms 96644 KB Output is correct
4 Correct 110 ms 96644 KB Output is correct
5 Correct 227 ms 96644 KB Output is correct
6 Correct 1309 ms 104044 KB Output is correct
7 Correct 36 ms 104044 KB Output is correct
8 Correct 35 ms 104044 KB Output is correct
9 Correct 5 ms 104044 KB Output is correct
10 Correct 3 ms 104044 KB Output is correct
11 Correct 35 ms 104044 KB Output is correct
12 Correct 5 ms 104044 KB Output is correct
13 Correct 75 ms 104044 KB Output is correct
14 Correct 46 ms 104044 KB Output is correct
15 Correct 34 ms 104044 KB Output is correct
16 Correct 34 ms 104044 KB Output is correct
17 Correct 199 ms 104044 KB Output is correct
18 Correct 136 ms 104044 KB Output is correct
19 Correct 117 ms 104044 KB Output is correct
20 Correct 90 ms 104044 KB Output is correct
21 Correct 216 ms 104044 KB Output is correct
22 Correct 228 ms 104044 KB Output is correct
23 Correct 337 ms 104044 KB Output is correct
24 Correct 207 ms 104044 KB Output is correct
25 Correct 612 ms 104044 KB Output is correct
26 Correct 1074 ms 107752 KB Output is correct
27 Correct 1016 ms 109468 KB Output is correct
28 Correct 1241 ms 109468 KB Output is correct
29 Correct 1063 ms 109468 KB Output is correct
30 Correct 1132 ms 109468 KB Output is correct
31 Correct 997 ms 109468 KB Output is correct
32 Correct 1120 ms 109468 KB Output is correct