Submission #1215686

#	Time	Username	Problem	Language	Result	Execution time	Memory
1215686		behesht	Tracks in the Snow (BOI13_tracks)	C++20	100 / 100	978 ms	320464 KiB

tracks

#include <bits/stdc++.h>

#define d1(x)                cout << #x << " : " << x << endl << flush
#define d2(x, y)             cout << #x << " : " << x << "   " << #y << " : " << y << endl << flush
#define d3(x, y, z)          cout << #x << " : " << x << "   " << #y << " : " << y << "   " << #z << " : " << z << endl << flush
#define d4(x, y, z, a)       cout << #x << " : " << x << "   " << #y << " : " << y << "   " << #z << " : " << z << "    "<< #a << " : " << a << endl << flush
#define ld                   long double
#define ll                   long long
#define pb                   push_back
#define arr(x)               array <ll, x>
#define endl                 '\n'
#define int                  long long

using namespace std;

const int INF = 1e8 + 24 + (33 / 10); // 33 ---> 34
const int MAXN = 4e3 + 24 + (33 / 10); // 33 ---> 34

int dx[4] = {-0, -0, 1, -1};
int dy[4] = {1, -1, -0, -0};

int a[MAXN][MAXN];
int dis[MAXN][MAXN];

signed main(){
	
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	
	int n, m;
    cin >> n >> m;

    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= m; j++){

            char eli;
            cin >> eli;

            if(eli == 'F')
                a[i][j] = 1;

            else if(eli == 'R')
                a[i][j] = 2;
        }
    }

    for(int i = 0; i <= n; i++)
        for(int j = 0; j <= m; j++)
            dis[i][j] = INF;

    deque <arr(2)> q;
    q.push_front({1, 1});
    dis[1][1] = 0;
    int ans = 0;

    while(!q.empty()){

        auto [ux, uy] = q.front();
        q.pop_front();
        ans = max(ans, dis[ux][uy]);
        
        for(int i = 0; i < 4; i++){

            int vx = ux + dx[i];
            int vy = uy + dy[i];
            int w = (a[ux][uy] != a[vx][vy]);

            if(!a[vx][vy])
                continue;
            
            if(dis[vx][vy] > dis[ux][uy] + w){

                dis[vx][vy] = dis[ux][uy] + w;

                if(w)
                    q.pb({vx, vy});
                
                else 
                    q.push_front({vx, vy});
            }
        }
    }

    cout << ans + 1 << endl;
}

// Man hamooonam ke ye rooz...

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