Submission #856951

#	Time	Username	Problem	Language	Result	Execution time	Memory
856951		teesla	Tracks in the Snow (BOI13_tracks)	C++14	84.69 / 100	2106 ms	148136 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
const int maxn = 4005;
typedef pair<int,int> ii;
typedef pair<int, ii> iii;

int adj[maxn][maxn], vis[maxn][maxn];
int vx[4] = {0,1,0,-1}, vy[4] = {1,0,-1,0};
int h,w;


int dijkstra(){

    priority_queue<iii, vector<iii> , greater<iii>> q;
    vis[h][w] = 1;

    q.push({1,{h,w}});
    int maior = 1;

    while(!q.empty()){

        auto [a,b] = q.top();
        auto [x,y] = b;
        q.pop();

        if(vis[x][y] < a) continue;
        maior = max(maior, a);

        for(int i=0; i<4; i++){

            int xx = x + vx[i], yy = y + vy[i];
            if(adj[xx][yy] == 0) continue;

            int val = a;

            if(adj[x][y] != adj[xx][yy]) val += 1;

            if(vis[xx][yy] != 0 and vis[xx][yy] <= val) continue;
            vis[xx][yy] = val;
            q.push({val, {xx,yy}});
        }
    }
    return maior;
}

int main(){

     cin >> h >> w;


    for(int i=1; i<=h; i++){

        string s; cin >> s;

        for(int j =0; j<w; j++){

            int val = 0;
            if(s[j] == 'R') val = 1;
            else if(s[j] == 'F') val = 2;

            adj[i][j+1] = val;
        }

    }


    cout << dijkstra() << endl;
    return 0;
}

Compilation message (stderr)

tracks.cpp: In function 'int dijkstra()':
tracks.cpp:22:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   22 |         auto [a,b] = q.top();
      |              ^
tracks.cpp:23:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   23 |         auto [x,y] = b;
      |              ^

• Subtask 1: 30 / 30
• Subtask 2: 54.6875 / 70