제출 #769506

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
769506		Ellinor	Tracks in the Snow (BOI13_tracks)	C++14	75.94 / 100	2092 ms	201524 KiB

tracks

#include <bits/stdc++.h>
using namespace std;

#define rep(i,a,b) for(int i = (a); i < (b); i++)
typedef long long ll;

int H, W;
vector<string> grid;

vector<vector<ll>> visited; // bitset ?

priority_queue<vector<ll>> q;

void dfs(int hat, int wat, ll num)
{
    if (visited[hat][wat]>0) return;
    if (grid[hat][wat] == '.') return;
    visited[hat][wat] = num;

    char ch = grid[hat][wat];
    if (hat + 1 < H) {
        if (grid[hat + 1][wat] == ch) q.push({-num, hat + 1, wat});
        else q.push({-(num + 1), hat + 1, wat});
    }
    if (wat + 1 < W) {
        if (grid[hat][wat + 1] == ch) q.push({-num, hat, wat + 1});
        else q.push({-(num + 1), hat, wat + 1});
    }
    if (hat - 1 >= 0) {
        if (grid[hat - 1][wat] == ch) q.push({-num, hat - 1, wat});
        else q.push({-(num + 1), hat - 1, wat});
    }
    if (wat - 1 >= 0) {
        if (grid[hat][wat - 1] == ch) q.push({-num, hat, wat - 1});
        else q.push({-(num + 1), hat, wat - 1});
    }
}

int32_t main()
{
    cin>>H>>W;
    grid.assign(H, "");
    rep(i,0,H){
        cin>>grid[i];
    }

    visited.assign(H, vector<ll>(W, -1));
    q.push({-1,0,0});
    while(!q.empty())
    {
        vector<ll> x = q.top();
        q.pop();
        dfs(x[1], x[2], -(x[0]));
    }

    ll ans = 1;
    rep(i,0,H){
        rep(j,0,W){
            ans = max(ans, visited[i][j]);
        }
    }
    cout << ans;
}

• Subtask 1: 30 / 30
• Subtask 2: 45.9375 / 70