Submission #736922

#	Time	Username	Problem	Language	Result	Execution time	Memory
736922		ksu2009en	Awesome Arrowland Adventure (eJOI19_adventure)	C++14	100 / 100	46 ms	5720 KiB

adventure

#include <iostream>
#include <vector>
#include <string>
#include <math.h>
#include <cmath>
#include <iomanip>
#include <cstdio>
#include <algorithm>
#include <numeric>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <deque>
#include <bitset>
#include <cstring>
#include <unordered_map>
 
using namespace std;
typedef int ll;
 
ll dp[507][507], used[507][507];
string a[507];
 
char rotate(char c){
    if(c == 'N')
        return 'E';
    if(c == 'E')
        return 'S';
    if(c == 'S')
        return 'W';
    return 'N';
}
 
pair<ll, ll> move(ll &r, ll &c, char &v){
    if(v == 'N')
        return {r - 1, c};
    if(v == 'E')
        return {r, c + 1};
    if(v == 'S')
        return {r + 1, c};
    return {r, c - 1};
}
 
ll n, m;
 
void count_dp(ll &r, ll &c, ll step){
    if(r < 1 || c < 1 || r > n || c > m || dp[r][c] <= step){
        return;
    }
        
    if(a[r][c] == 'X'){
        if(r == n && c == m)
            dp[r][c] = step;
        return;
    }
    
    dp[r][c] = step;
    
    char v = a[r][c];
    
    for(int i = 0; i < 4; i++){
        auto y = move(r, c, v);
        if(y.first >= 1 && y.second >= 1 && y.first <= n && y.second <= m && dp[y.first][y.second] > step + i)
        count_dp(y.first, y.second, step + i);
        
        v = rotate(v);
    }
}
 
ll cost(char a, char b){
    for(int i = 0; i < 4; i++){
        if(a == b)
            return i;
        
        a = rotate(a);
    }
    return 0;
}
 
struct one{
    ll r, c, cost;
};

bool operator < (const one &p1, const one &p2){
    return p1.cost < p2.cost;
}
bool operator > (const one &p1, const one &p2){
    return p1.cost > p2.cost;
}
 
int main(){
    
    cin >> n >> m;
    
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        
         
        a[i] = "#" + a[i];
    }
    
    priority_queue<one, vector<one>, greater<one>> q;
    
    for(int i = 1; i <= n; i++)
        for(int j = 1; j <= m; j++)
            dp[i][j] = 1e9;
    
    dp[1][1] = 0;
    q.push({1, 1, 0});
    
    while(!q.empty()){
        auto v = q.top();
        q.pop();
        
        if(v.r == n && v.c == m){
            break;
        }
        
        if(used[v.r][v.c])
            continue;
        used[v.r][v.c] = 1;
        
        if(a[v.r][v.c] == 'X')
            continue;
        
        ll r = v.r, c = v.c;
        if(r - 1 >= 1 && cost(a[r][c], 'N') + v.cost < dp[r - 1][c]){
            dp[r - 1][c] = cost(a[r][c], 'N') + v.cost;
            q.push({r - 1, c, dp[r - 1][c]});
        }
        if(r + 1 <= n && cost(a[r][c], 'S') + v.cost < dp[r + 1][c]){
            dp[r + 1][c] = cost(a[r][c], 'S') + v.cost;
            q.push({r + 1, c, dp[r + 1][c]});
        }
        
        if(c - 1 >= 1 && cost(a[r][c], 'W') + v.cost < dp[r][c - 1]){
            dp[r][c - 1] = cost(a[r][c], 'W') + v.cost;
            q.push({r, c - 1, dp[r][c - 1]});
        }
        if(c + 1 <= m && cost(a[r][c], 'E') + v.cost < dp[r][c + 1]){
            dp[r][c + 1] = cost(a[r][c], 'E') + v.cost;
            q.push({r, c + 1, dp[r][c + 1]});
        }
    }
    
    if(dp[n][m] >= (ll)(1e9))
        dp[n][m] = -1;
    
    cout << dp[n][m] << endl;
     
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 12 / 12
• Subtask 4: 16 / 16
• Subtask 5: 50 / 50