Submission #1123476

#	Time	Username	Problem	Language	Result	Execution time	Memory
1123476		tintingyn21	Pohlepko (COCI16_pohlepko)	C++20	0 / 80	320 ms	128772 KiB

pohlepko

// author : daohuyenchi



#include <bits/stdc++.h>

using namespace std;

#define ull unsigned long long
#define db double
#define i32 int32_t  
#define i64 int64_t 
#define ll long long
// 
#define fi first
#define se second


//                                      #define int long long    // consider carefully


//
#define pii pair<int, int>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define pil pair<int, ll> 
#define PAIR make_pair 
//                                      TIME IS LIMITED ...  
#define  rep(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define repd(i, b, a) for (int i = (b), _a = (a); i >= _a; --i)
#define repv(v, H) for(auto &v: H)
//                                      REFLECT ON THE PAST ...
#define RESET(c, x) memset(c, x, sizeof(c))
#define MASK(i) (1LL << (i))
#define BIT(mask, i) (((mask) >> (i)) & 1LL)
#define ONBIT(mask, i) ((mask) | (1LL << (i)))
#define OFFBIT(mask, i) ((mask) &~ (1LL << (i)))
#define COUNTBIT __builtin_popcountll
//                                      30 / 1 / 2024 ? love is zero... start from zero 
#define PB push_back
#define EB emplace_back
#define vi vector<int>
#define vll vector<ll>
#define lwb lower_bound
#define upb upper_bound
#define all(v) (v).begin(), (v).end()
#define special(H) (H).resize(distance(H.begin(), unique(all(H))))
//                                      
#define sp ' ' 
#define nl '\n'
#define EL {cerr << '\n';}
#define yes "YES"
#define no "NO"
#define Log2(n) (63 - __builtin_clzll(n))
#define left __left__
#define right __right__ 

//____________________________________________________________________


template <class X, class Y> bool maximize(X &a, const Y &b) {
    if(a < b) return a = b, true;
    return false;
}

template <class X, class Y> bool minimize(X &a, const Y &b) {
    if(a > b) return a = b, true;
    return false;
}

template <class... T>
void print(T&&... n) {
    using exp = int[];
    exp{0, (cerr << n << sp, 0)...};
    cerr << nl;
}

template <class... T>
void print2(T&&... n) {
    using exp = int[];
    exp{0, (cerr << n << sp, 0)...};
    // cerr << sp;
}

template <class T, class... C>
void assign(int n, T v, C&&... a) {
    using e = int[];
    e{(a.assign(n, v), 0)...};
}

template <class... C>
void resize(int n, C&&... a) {
    using e = int[];
    e{(a.resize(n), 0)...};
}

template <class T>
using vector2d = vector<vector<T>>;
template <class T>
using vector3d = vector<vector2d<T>>;

template <class T> int ssize(T &a) { return (int) a.size(); }


//____________________________________________________________________


mt19937 rng(chrono::steady_clock().now().time_since_epoch().count());

const int MOD      = 1000000007;
// const int MOD[2] = {1000000009, 998244353};

template<class X> void modmize(X &x, int cur_Mod = MOD) {
    if(x >= cur_Mod) x -= cur_Mod;
    if(x < 0) x += cur_Mod;
}

const long long oo = 1e18 + 7;
const int INF      = 2e9;
const int nmax     = 1e6 + 10;
const int MAX      = 2e5;
const int base     = 311;
const db eps       = 1e-6;
const int block    = 500;
static const double PI = acos(-1.0);

//____________________________________________________________________


int n, m;
vector2d <char> a;

int dx[] = {0, 1};
int dy[] = {1, 0};

vector2d <int> dp;
int solve(int x, int y) {
    if (x == n && y == m) return 1;
    auto &ret = dp[x][y];
    if (ret != -1) return ret;
    int cur = 0;
    for (int k = 0; k < 2 && cur == 0; ++k) {
        int nx = x + dx[k];
        int ny = y + dy[k];
        if (nx > n || ny > m || a[nx][ny] == '#') continue;
        cur = solve(nx, ny);
    }
    return ret = cur;
}

vector <pii> pat;
void trace(int x, int y) {
    pat.push_back({x, y});
    if (x == n && y == m) return;

    priority_queue <pii> pq;
    for (int k = 0; k < 2; ++k) {
        int nx = x + dx[k];
        int ny = y + dy[k];
        if (nx > n || ny > m || a[nx][ny] == '#') continue;
        if (solve(nx, ny)) {
            pq.push({- a[nx][ny], k});
        }
    }

    int k = pq.top().se;
    int nx = x + dx[k];
    int ny = y + dy[k];
    trace(nx, ny);
    return;
}

struct Node {
    int t, x, y;

    bool operator < (const Node &ot) const {
        if (t != ot.t) return t > ot.t;
        else {
            return a[x][y] >= a[ot.x][ot.y];
        }
    } 
} ; 

set <pii> s[nmax * 2];

void tintingyn() {

    cin >> n >> m;
    assign(n + 2, vector <char>(m + 2, 'a'), a);

    rep (i, 1, n) rep (j, 1, m) {
        cin >> a[i][j];
    }

    assign(n + 2, vector <int>(m + 2, -1), dp);

    queue <pii> q;
    vector2d <bool> vis;
    assign(n + 2, vector <bool> (m + 2, 0), vis);

    vector <int> d(n + m + 2, -1);
    d[1] = a[1][1] - 'a';

    priority_queue <Node> pq;
    pq.push({1, 1, 1});


    while (pq.empty() == 0) {
        auto cur_v = pq.top();
        pq.pop();
        int t = cur_v.t;
        int x = cur_v.x;
        int y = cur_v.y;
        if (d[t] != a[x][y] - 'a') continue;
        // print(t, x, y);
        rep (k, 0, 1) {
            int nx = x + dx[k];
            int ny = y + dy[k];
            if (nx > n || ny > m || a[nx][ny] == '#' || solve(nx, ny) == 0) continue;
            if (d[t + 1] == -1 || d[t + 1] >= a[nx][ny] - 'a') {
                if (s[t + 1].count(PAIR(nx, ny))) continue;
                d[t + 1] = a[nx][ny] - 'a';
                pq.push({t + 1, nx, ny}); 
                s[t + 1].insert({nx, ny});
            }
        }
    }

    rep (i, 1, n + m - 1) {
        cout << (char) (d[i] + 'a');
    }
    
}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    //________________________________________________________________

    #define TASK "MINTRIX"
    if(fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }

    //________________________________________________________________
    
    //  CODE FROM HERE ...! 





    int num_test = 1; 
    // cin >> num_test;

    while(num_test--) {

        tintingyn();

    }


    cerr << '\n' << "Time elapsed: " << (1.0 * clock() / CLOCKS_PER_SEC) << " s\n" << nl;

    return 0;
}

Compilation message (stderr)

pohlepko.cpp: In function 'int main()':
pohlepko.cpp:246:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  246 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
pohlepko.cpp:247:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  247 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 80