Submission #344193

#	Time	Username	Problem	Language	Result	Execution time	Memory
344193		ak2006	Tracks in the Snow (BOI13_tracks)	C++14	82.50 / 100	2091 ms	120000 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vc = vector<char>;
using vvc = vector<vc>;
const ll mod = 1e9 + 7,inf = 1e18;
const vi dx = {1,-1,0,0},dy = {0,0,1,-1};
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
int main()
{
    int w,h;
    cin>>w>>h;
    vvc g(w,vc(h));
    for (int i = 0;i<w;i++)for (int j = 0;j<h;j++)cin>>g[i][j];
    vvi dp(w,vi(h,1e9));
    dp[0][0] = 0;
    priority_queue<vi>q;
    q.push({0,0,0});
    while (!q.empty()){
        int ci = q.top()[1],cj = q.top()[2];
        q.pop();
        for (int x = 0;x<4;x++){
            int ni = ci + dx[x],nj = cj + dy[x];
            if (ni < 0 || nj < 0 || ni >= w || nj >= h || g[ni][nj] == '.')continue;
            int cost = (g[ci][cj] == g[ni][nj] ? 0 : 1);
            if (dp[ni][nj] <= dp[ci][cj] + cost)continue;
            dp[ni][nj] = dp[ci][cj] + cost;
            q.push({-dp[ni][nj],ni,nj});
        }
    }
    int ans = 0;
    for (int i = 0;i<w;i++)
        for (int j = 0;j<h;j++)
            ans = max(ans,dp[i][j] == 1e9 ? 0 : dp[i][j]);
    cout<<ans + 1;
    return 0;
}

• Subtask 1: 30 / 30
• Subtask 2: 52.5 / 70