Submission #367824

#	Time	Username	Problem	Language	Result	Execution time	Memory
367824		phathnv	Selotejp (COCI20_selotejp)	C++11	110 / 110	42 ms	512 KiB

Main

#include <bits/stdc++.h>

#define mp make_pair
#define X first
#define Y second
#define taskname "Selotejp"

using namespace std;

typedef long long ll;
typedef pair <int, int> ii;

const int M = 1001;
const int N = 10;
const int INF = 1e9;

void minimize(int &x, int y){
    if (x > y)
        x = y;
}

int m, n, closedInRow[M], dp[2][1 << N], f[1 << N], cost[1 << N];

void readInput(){
    cin >> m >> n;
    for(int i = 1; i <= m; i++){
        string s;
        cin >> s;
        for(int j = 0; j < n; j++)
            if (s[j] == '#')
                closedInRow[i] |= (1 << j);
    }
}

void solve(){
    for(int mask = 0; mask < (1 << n); mask++){
        cost[mask] = 0;
        for(int i = 0; i < n; i++){
            cost[mask] += (mask >> i) & 1;
            if (i > 0)
                cost[mask] -= (mask >> (i - 1)) & (mask >> i) & 1;
        }
    }

    for(int id = 0; id < 2; id++)
        for(int mask = 0; mask < (1 << n); mask++)
            dp[id][mask] = INF;
    dp[0][0] = 0;

    for(int i = 1; i <= m; i++){
        int id = i & 1;
        for(int mask = 0; mask < (1 << n); mask++)
            f[mask] = dp[id][mask] = INF;
        for(int mask = 0; mask < (1 << n); mask++)
            minimize(f[mask & closedInRow[i]], dp[id ^ 1][mask]);
        for(int mask = 0; mask < (1 << n); mask++)
            for(int j = 0; j < n; j++)
                minimize(f[mask | (1 << j)], f[mask] + 1);
        for(int mask = (1 << n) - 1; mask >= 0; mask--)
            for(int j = 0; j < n; j++)
                minimize(f[mask & (~(1 << j))], f[mask]);

        for(int mask = 0; mask < (1 << n); mask++){
            if ((closedInRow[i] & mask) != mask)
                continue;
            dp[id][mask] = f[mask] + cost[closedInRow[i] ^ mask];
        }
    }

    int res = INF;
    for(int mask = 0; mask < (1 << n); mask++)
        res = min(res, dp[m & 1][mask]);
    cout << res;
}

int main(){
    if (fopen(taskname".inp", "r")){
        freopen(taskname".inp", "r", stdin);
        freopen(taskname".out", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(nullptr);
    readInput();
    solve();
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:78:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   78 |         freopen(taskname".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:79:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   79 |         freopen(taskname".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 35 / 35
• Subtask 2: 35 / 35
• Subtask 3: 40 / 40