REFORM – SPOJ

Đề bài: http://vn.spoj.com/problems/REFORM/

Thuật toán:

• (đang cập nhập)

Code:

#include 
#define FORE(i, a, b) for(int i = a; i <= b; i++)
#define FORD(i, a, b) for(int i = a; i >= b; i--)
#define FOR(i, a, b) for(int i = a; i < b; i++)
const int MAXN = 1e5 * 5;
const int INF = 1e9 + 7;

using namespace std;

int n, m;
bool a[50][50];
typedef pair ii;
vector< ii > s1, s2;
int dem;
bool Free[50];

inline void duyet(int u)
{
    //cout< 0){
        duyet(v);
    }
}

vector< int > adj[MAXN];
int Low[MAXN], Num[MAXN], Count = 0, Pa[MAXN], C[MAXN];

inline void dfs(int u)
{
    Count++;
    Num[u] = Count;
    Low[u] = n + 1;
    C[u] = 1;
    FOR(i, 0, adj[u].size()){
        int v = adj[u][i];
        if (Pa[v] == 0){
            Pa[v] = u;
            dfs(v);
            C[u] += C[v];
            Low[u] = min(Low[u], Low[v]);
        } else
            if (Pa[u] != v) Low[u] = min(Low[u], Num[v]);
    }
}

long long sd[3];
int main()
{
    ios::sync_with_stdio(0); cin.tie(0);
    #ifndef ONLINE_JUDGE
    freopen("REFORM.inp", "r", stdin);
    freopen("REFORM.out", "w", stdout);
    #endif //MIKELHPDATKE
    cin >> n >> m;

    if (n <= 20){
        FORE(i, 1, m){
            int x, y;
            cin >> x >> y;
            a[x][y] = 1;
            a[y][x] = 1;
        }
        long long ans = 0;
        FORE(x, 1, n) FORE(y, x + 1, n) if (a[x][y] == 1){
            s2.push_back(ii(x, y));
        } else s1.push_back(ii(x, y));
        FOR(i, 0, s1.size())
        FOR(j, 0, s2.size()){
            int u1 = s1[i].first, v1 = s1[i].second;
            int u2 = s2[j].first, v2 = s2[j].second;
            a[u1][v1] = 1; a[v1][u1] = 1;
            a[u2][v2] = 0; a[v2][u2] = 0;
            memset(Free, 1, sizeof(Free));
            dem = 0;
           // cout<> u >> v;
            adj[u].push_back(v);
            adj[v].push_back(u);
        }
        int dlt = 0;
        FORE(u, 1, n) if (Pa[u] == 0){
            Pa[u] = -1;
            Count = 0;
            dfs(u);
            dlt++;
            sd[dlt] = Count;
        }
        //cout< 2){
            cout << 0 << endl;
            return 0;
        }

        //FORE(u, 1, n) cout << C[u]<<" ";cout<