Submission #736878

#	Time	Username	Problem	Language	Result	Execution time	Memory
736878		ksu2009en	Awesome Arrowland Adventure (eJOI19_adventure)	C++14	Compilation error	0 ms	0 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;

ll count_dp(ll r, ll c){
    if(r < 1 || c < 1 || r > n || c > m || dp[r][c] == -2 || (a[r][c] == 'X' && (r != n || c != m))){ // cycle
        return -1;
    }
    if(r == n && c == m){
        return dp[r][c] = 0;
    }
    
    if(dp[r][c] != -1)
        return dp[r][c];
    
    
    ll mn = 1e18;
    dp[r][c] = -2;
    
    char v = a[r][c];
    ll can = 0;
    
    for(int i = 0; i < 4; i++){
        auto y = move(r, c, v);
        ll cnt = count_dp(y.first, y.second);
        if(cnt != -1){
            mn = min(mn, i + cnt);
            can++;
        }
        
        v = rotate(v);
    }
    
    if(can == 0){
        mn = -1;
        return dp[r][c] = mn;
    }
    
    dp[r][c] = mn;
    for(int i = 0; i < 4; i++){
        auto y = move(r, c, v);
        ll cnt = count_dp(y.first, y.second);
        
        v = rotate(v);
    }
    
    return dp[r][c] = mn;
}

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 == 0){ // 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;
    
    return dp2[n][m];
}


int main(){
    cin >> n >> m;
    
    
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        a[i] = "#" + a[i];
    }
    
    if(n == 2){
        cout << n2() << endl;
        return 0;
    }
    
    for(int i = 1; i <= n; i++)
        for(int j = 1; j <= m; j++)
            dp[i][j] = -1;
    
    count_dp(1, 1);
    if(dp[1][1] == (ll)(1e18) || dp[1][1] == -2)
        dp[1][1] = -1;
  
    cout << dp[1][1] << endl;
     
    return 0;
}
/*
 2 5
 ESNWX
 SNXEX
 
 */
/*
 2 4
  EWEW
  EWXX
 
 */

/*
 2 4
 EWEW
 EWEX
 
 */

Compilation message (stderr)

adventure.cpp: In function 'll count_dp(ll, ll)':
adventure.cpp:84:12: warning: unused variable 'cnt' [-Wunused-variable]
   84 |         ll cnt = count_dp(y.first, y.second);
      |            ^~~
adventure.cpp: In function 'll n2()':
adventure.cpp:105:32: error: expected ')' before ':' token
  105 |     dp2[1][1] = (a[1][1] == 'X' : 1e9 ? 0);
      |                 ~              ^~
      |                                )