Submission #736903

#	Time	Username	Problem	Language	Result	Execution time	Memory
736903		ksu2009en	Awesome Arrowland Adventure (eJOI19_adventure)	C++14	50 / 100	2058 ms	816 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 long long ll;

ll dp[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;
    }
    
    //cout << r << ' ' << c << endl;
    
    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);
       // cout << r << ' ' << c << ' ' << y.first << ' ' << y.second << "   " << step + i << endl;
        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;
}

ll n2(){
    vector<vector<ll>>dp2(n + 1, vector<ll>(m + 1, 1e9));
    
    dp2[1][1] = (a[1][1] == 'X' ? 1e9 : 0);
    dp2[2][1] = (a[2][1] == 'X' ? 1e9 : cost(a[1][1], 'S'));
    
    for(int j = 2; j <= m; j++){
        for(int i = 1; i <= n; i++){
            if(a[i][j] == 'X' && (i != n || j != m))
                continue;
            
            // go from left:
            dp2[i][j] = dp2[i][j - 1] + cost(a[i][j - 1], 'E');
            
            ll cnt = 0;
            
            if(i == 1){ // go from (i + 1, j)
                cnt = dp2[i + 1][j - 1] + cost(a[i + 1][j - 1], 'E') + cost(a[i + 1][j], 'N');
            }
            else{
                cnt = dp2[i - 1][j - 1] + cost(a[i - 1][j - 1], 'E') + cost(a[i - 1][j], 'S');
            }
            
            
            dp2[i][j] = min(dp2[i][j], cnt);
        }
    }
    
  
    if(dp2[n][m] >= 1e9)
        dp2[n][m] = -1;
    
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= m; j++)
            cout << dp2[i][j] << ' ';
        cout << endl;
    }
    
    return dp2[n][m];
}


int main(){
    srand(time(0));
   // cin >> n >> m;
    
   // ll t = 10000;
    ll t = 1;
    while(t--){
        //n = 2, m = 1 + rand() % 12;
        cin >> n >> m;
        
        for(int i = 1; i <= n; i++){
            cin >> a[i];
            /*
            for(int j = 1; j <= m; j++){
                ll c = rand() % 4;
                if(c == 0)
                    a[i] += 'N';
                else if(c == 1)
                    a[i] += 'E';
                else if(c == 2)
                    a[i] += 'S';
                else
                    a[i] += 'W';
            }
             */
             
            a[i] = "#" + a[i];
        }
        
        for(int i = 1; i <= n; i++)
            for(int j = 1; j <= m; j++)
                dp[i][j] = 1e9;
        
        count_dp(1, 1, 0);
        if(dp[n][m] == (ll)(1e9))
            dp[n][m] = -1;
        
        cout << dp[n][m] << endl;
        
        return 0;
        if(dp[1][1] == (ll)(1e18) || dp[1][1] == -2)
            dp[1][1] = -1;
        
        for(int i = 1; i <= n; i++){
            for(int j = 1; j <= m; j++){
                cout << dp[i][j] << ' ';
                if(i == 1 && j >= 5 && j <= 7)
                    cout << ' ';
            }
            cout << endl;
        }
        cout << endl;
      
        if(dp[1][1] != n2()){
            cout << dp[1][1] << ' ' << n2() << endl;
            cout << n << ' ' << m << endl;
            
            for(int i = 1; i <= n; i++){
                for(int j = 1; j <= m; j++)
                    cout << a[i][j];
                cout << endl;
            }
            return 0;
        }
    }
     
    return 0;
}
/*
 2 13
 SSNWNEWESEWWE
 WSENESSWNNSWW
 */
/*
 2 11
 W W W E S N N S S E W
 W E E N W W E S S W W
 
 */
/*
 2 5
 EXNWS
 SEEXX
 
 */
/*
 2 4
  EWEW
  EWXX
 
 */

/*
 2 4
 EWEW
 EWEX
 
 */

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 12 / 12
• Subtask 4: 16 / 16
• Subtask 5: 0 / 50