USACO Chapter 2 Section 2.1

准备期末考试 停了一个月……现在开始继续刷

 

 

/*
ID:xiekeyi1
PROG:castle
LANG:C++
*/
#include<bits/stdc++.h>
using namespace std ;
const int maxn = 55;

int graph[maxn][maxn][5];
int roomsize[maxn*maxn] ;
int vis[maxn][maxn];
int m , n , color , maxsize ; 
int dx[] = { 1 ,  0 , -1 , 0 } ;
int dy[] = { 0 , 1 , 0 , -1 };
int nowsize ; 
int ans_row , ans_col ; 
char dir ; 
void scan()
{
    cin >> m >> n ;
    for( int i = 1 ; i <= n ; i++)
        for( int j = 1 ; j <= m ; j++)
        {
            int t ;
            cin >> t ;
            for( int  k = 3 ; k >= 0 ; k--)
                graph[i][j][k] = t % 2 , t = t >> 1 ;
        }
}

void floodfill( int x , int y )
{
    vis[x][y] = true ;
    roomsize[color]++;
    graph[x][y][4] = color ; 
    for( int i = 0 ; i < 4 ; i++)
    {
        int nx = x + dx[i] ;
        int ny = y + dy[i];
        if( nx < 1 || ny < 1 || nx > n || ny > m ) continue ;
        if( vis[nx][ny] || graph[x][y][i] ) continue ;
        floodfill(nx,ny);
    }
}

void merge( int x , int y )
{
    int sum = 0 ;
    if( x >= 2 && graph[x-1][y][4] != graph[x][y][4] )
    {
        sum = roomsize[ graph[x-1][y][4] ] + roomsize[ graph[x][y][4] ] ;
        if( sum > maxsize)
            maxsize=sum,ans_row=x,ans_col=y,dir='N' ; 
    }
    if( y < m && graph[x][y+1][4] != graph[x][y][4] )
    {
        sum = roomsize[ graph[x][y+1][4] ] + roomsize[ graph[x][y][4] ] ;
        if( sum > maxsize )
            maxsize = sum , ans_row = x , ans_col = y , dir = 'E' ;
    }
}

int main()
{
    freopen("castle.in","r",stdin);
    freopen("castle.out","w",stdout);
    scan();
    for( int i = 1 ; i <= n ; i++)
        for( int j = 1 ; j <= m ; j++)
        {
            if( !vis[i][j] )
            {
                roomsize[ color ] = 0 ;
                floodfill( i , j );
                color++;
            }
        }
    for( int i = 0 ; i < color ; i++)
        nowsize = max( nowsize , roomsize[ i ] ) ; 
    for( int i = 1 ; i <= m ; i++)
        for( int j = n  ; j >= 1 ; j--)
            merge(j,i);

    cout << color << endl << nowsize << endl << maxsize << endl
         << ans_row << ' ' << ans_col << ' ' << dir << endl ;
    return 0 ;
}

 

 

 

/*
ID:xiekeyi1
PROG:frac1
LANG:C++
*/

#include<bits/stdc++.h>
using namespace std ;
const int maxn = 170 ; 
struct node
{
    int fenzi , fenmu ;
    long double value ;
}x[maxn*maxn];

bool operator < ( struct node a , struct node b ) 
{
    return a.value < b.value ;
}

int gcd( int a , int b )
{
    if( b == 0 )
        return a ;
    if( a == 0 )
        return b ; 
    else
        return gcd( b , a % b ) ;
}

int main()
{
    freopen("frac1.in","r",stdin);
    freopen("frac1.out","w",stdout);
    int n ;
    cin >> n ;
    int cnt = 0 ; 
    for( int i = 0 ; i <= n ; i++)
        for( int j = 1 ; j <= n ; j++)
            if( gcd( i , j ) == 1 && ( (i+0.0) / j ) <= 1  )
                x[cnt].fenzi = i , x[cnt].fenmu = j , x[cnt].value = (x[cnt].fenzi + 0.0)  / x[cnt].fenmu , cnt++;

    sort(x,x+cnt);
    for( int i = 0 ; i < cnt ; i++)
        printf("%d/%d\n",x[i].fenzi,x[i].fenmu);
    return 0 ; 
}

            

 

 

/*
ID:xiekeyi1
PROG:sort3
LANG:C++
*/
#include<bits/stdc++.h>
using namespace std ;
const int maxn = 1010 ;
int a[maxn] , b[maxn];
int c[5][5] ;

int main()
{
    freopen("sort3.in","r",stdin);
    freopen("sort3.out","w",stdout);
    int n ;
    cin >> n ;
    for( int i = 1 ; i <= n ; i++)
    {
        cin >> a[i] ;
        b[i] = a[i] ;
    }

    sort( b+1 , b+1+n ) ;

    for( int i = 1 ; i <= n ; i++)
        if( a[i] != b[i] )
            c[ b[i] ][ a[i] ]++;

    int ans = 0 ; 
    for( int i = 1 ; i <= 3 ; i++)
    {
        for( int j = 1 ; j <= 3 ;j++)
        {
            if( c[i][j] && c[j][i] )
            {
                int t = min( c[i][j] , c[j][i] );
                c[i][j] -= t , c[j][i] -=t , ans+=t ;
            }
        }
    }

    ans+= c[1][2] * 2 ;
    ans+= c[1][3] * 2 ;
    cout << ans << endl ;
    return 0 ; 
}

 

 

/*
ID:xiekeyi1
PROG:holstein
LANG:C++
*/
#include<bits/stdc++.h>
using namespace std ;
const int maxn = 30 ; 
int v , vv[maxn] , g , gg[maxn][maxn];

void init()
{
    cin >> v ;
    for( int i = 1 ; i <= v ; i++)
        cin >> vv[i];
    cin >> g ;
    for( int i = 1 ; i <= g ; i++)
        for( int j = 1 ; j <= v ; j++)
            cin >> gg[i][j];
}

bool flag = false ;
int num[maxn];
int cnt = 0 ;
int k = 1 ; 
void work() 
{
    int a[30] = {0};
    for( int i = 1 ; i <= cnt  ; i++)
        for( int j = 1 ; j <=  v ; j++)
            a[j] += gg[ num[i] ][j] ; 
    for( int i = 1 ; i <= v ; i++)
        if( a[i] < vv[i] )
            return ;

    flag = true ; 
    cout << cnt ;
    for( int i = 1 ; i <= cnt ; i++)
        cout << ' ' << num[i] ;
    cout << endl ;
}

void dfs( int t )
{
    if( flag || t > g ) return ;
    if( cnt >= k )
    {
        work() ;
        return ;
    }

    cnt++;
    num[cnt] = t + 1 ;
    dfs( t + 1 ) ;
    cnt--;
    dfs( t + 1 ) ; 
    return ; 
}


int main()
{
    freopen("holstein.in","r",stdin);
    freopen("holstein.out","w",stdout);
    init() ;
    while( !flag )
    {
        dfs(0);
        k++;
    }
    return  0 ; 
}

 

 

/*
ID:xiekeyi1
PROG:hamming
LANG:C++
 */
#include<bits/stdc++.h>
using namespace std ;

bool judge( int b , int n , int d , int aj)
{
    bitset<8> judge( n ^ aj ) ;
    int t1 = 0 , t2 = 0 ;
    for( int i = 0  ; i < b ; i++)
        if( judge.test( i ) )
            t1++;
    if( t1 < d )
        return false ; 
    //    judge.flip();
    //    for( int i = 0 ; i < b ; i++)
    //        if( judge.test( i ) ) 
    //            t2++;
    //    if( t1 < d && t2 < d )
    //        return false ;
    return true ; 

    //    int t1 = judge.count();
    //    judge.flip();
    //    int t2 = judge.count();
    //    if( t1 !=  d && t2 != d )
    //        return false ;
    //    return true ; 
}


int main()
{
    freopen("hamming.in","r",stdin);
    freopen("hamming.out","w",stdout);
    int n , b , d ;
    cin >> n >> b >> d ;
    int cnt = 0 ;
    vector<int> a;
    a.push_back(0);
    int i = 0 ; 
    while( a.size() != n)
    {
        for( ; i <= 300; ) 
        {
            i++;
            //cout << "Debug: " << i << endl ; 
            bool flag = true ; 
            for( int j = 0 ; j < a.size() ; j++)
            {
                //bitset<8> judge( i ^ a[j] ) ; 
                if( !judge( b, i , d , a[j] ) ) 
                {
                    flag = false ;
                    break ;
                }
            }
            if( flag )
            {
                a.push_back(i) ;
                //cout << "Debug:" << i << endl ; 
                break ; 
            }

        }
    }
    int tcnt = 0 ;
    for( int i = 0 ; i < a.size() ; i++)
    {
        ++tcnt;
        if( tcnt == 1 )
            cout << a[i] ;
        else if( tcnt != 10  )
            cout << ' ' << a[i] ;
        else if( tcnt == 10 )
        {
            tcnt = 0 ;
            cout <<  ' ' << a[i] << endl ;
        }
    }
    if( tcnt != 0  )
        cout << endl ;
    return 0 ; 
}