Submission #791687

#	Time	Username	Problem	Language	Result	Execution time	Memory
791687		dwuy	Tracks in the Snow (BOI13_tracks)	C++14	41.25 / 100	678 ms	235804 KiB

tracks

/// (⌐■_■): "who's nvpu, dwuy?"
///  dwuy : "revolym"
#include <bits/stdc++.h>

#define fastIO ios_base::sync_with_stdio(false); cin.tie(NULL)
#define file(a) freopen(a".inp","r",stdin); freopen(a".out", "w",stdout)
#define fi first
#define se second
#define endl "\n"
#define len(s) int32_t(s.length())
#define MASK(k)(1LL<<(k))
#define TASK ""
#define int long long

using namespace std;

typedef tuple<int, int, int> tpiii;
typedef pair<double, double> pdd;
typedef pair<int, int> pii;
typedef long long ll;

const long long OO = 1e18;
const int MOD = 1e9 + 7;
const int INF = 1e9;

const int MX = 4005;
const int dx[] = {0, 0, -1, 1};
const int dy[] = {-1, 1, 0, 0};

int n, m;
string a[MX];
int d[MX][MX];

void nhap(){
    cin >> n >> m;
    for(int i=0; i<n; i++) cin >> a[i];
}

void solve(){
    deque<pii> Q;
    d[1][1] = 1;
    Q.push_front({1, 1});
    int ans = 0;
    while(Q.size()){
        int x, y;
        tie(x, y) = Q.front();
        Q.pop_front();
        ans = max(ans, d[x][y]);
        for(int i=0; i<4; i++){
            int u = x + dx[i];
            int v = y + dy[i];
            if(u<0 || u>=n || v<0 || v>=m || d[u][v]!=0 || a[u][v]=='.') continue;
            if(a[u][v] == a[x][y]){
                d[u][v] = d[x][y];
                Q.push_front({u, v});
            }
            else{
                d[u][v] = d[x][y] + 1;
                Q.push_back({u, v});
            }
        }
    }
    cout << ans;
}

int32_t main(){
    fastIO;
    //file(TASK);

    nhap();
    solve();

    return 0;
}

• Subtask 1: 15 / 30
• Subtask 2: 26.25 / 70