Submission #534369

#	Time	Username	Problem	Language	Result	Execution time	Memory
534369		aadit_ambadkar	Tracks in the Snow (BOI13_tracks)	C++17	0 / 100	2092 ms	78848 KiB

tracks

/*
    This code belongs to Aadit Ambadkar
    Date: 2022-03-07 21:34:47
    Problem: tis
*/
#include <bits/stdc++.h>
using namespace::std;

typedef long long ll;
#define F0R(i, n) for (int i = 0; i < n; i++)
#define R0F(i, n) for (int i = n-1; i >= 0; i--)
#define FOR(i, a, n) for (int i = a; i < n; i++)
#define pb push_back
#define fastio ios::sync_with_stdio(0); cin.tie(0)
#define MOD 1000000007
#define FF first
#define SS second

int n, m;
int board[4005][4005];
bool vis[4005][4005];

int main() {
    fastio;
    cin >> n >> m;
    string s;
    F0R(i, n) {
        cin >> s;
        F0R(j, m) {
            if (s[i]=='F') board[i][j]=1;
            else if (s[i]=='R') board[i][j]=2;
            else board[i][j]=0;
            vis[i][j]=false;
        }
    }
    priority_queue<pair<int, pair<int, int>>, vector<pair<int, pair<int, int>>>, greater<pair<int, pair<int, int>>>> pq;
    pq.push({1, {0, 0}});
    int ans = 0;
    while (!pq.empty()) {
        auto p = pq.top(); pq.pop();
        int g = p.FF, u = p.SS.FF, v = p.SS.SS;
        if (vis[u][v]) continue;
        ans = max(ans, g);
        vis[u][v]=true;
        if (u > 0 && !vis[u-1][v] && board[u-1][v]!=0) pq.push({g+((board[u][v]==board[u-1][v]) ? 0 : 1), {u-1, v}});
        if (u < n-1 && !vis[u+1][v] && board[u+1][v]!=0) pq.push({g+((board[u][v]==board[u+1][v]) ? 0 : 1), {u+1, v}});
        if (v > 0 && !vis[u][v-1] && board[u][v-1]!=0) pq.push({g+((board[u][v]==board[u][v-1]) ? 0 : 1), {u, v-1}});
        if (v < m-1 && !vis[u][v+1] && board[u][v+1]!=0) pq.push({g+((board[u][v]==board[u][v+1]) ? 0 : 1), {u, v+1}});
    }
    cout << ans;
    return 0;
}

• Subtask 1: 0 / 30
• Subtask 2: 0 / 70