SRM 447

250:

/* * Author : Praesidio * Create Time : 2014-05-11 14:38:38 * File Name : srm447250.cpp */#include <cstdio>#include <cstdlib>#include <cstring>#include <iostream>#include <algorithm>#include <string>#include <set>#include <vector>#include <map>#include <stack>#include <ctime>#include <sstream>using namespace std;#define inf 0x3f3f3f3f#define eps 1e-10#define sqr(x) ((x)*(x))#define clr(x) memset(x,0,sizeof(x))typedef long long ll;template<class T> string toString(T n){ostringstream ost;ost<<n;ost.flush();return ost.str();}int toInt(string s){int r=0;istringstream sin(s);sin>>r;return r;}const int dx[8] = { -2 , -2 , -1 , -1 , 1 , 1 , 2 , 2 };const int dy[8] = { -1 , 1 , -2 , 2 , -2 , 2 , -1 , 1 };int n,ans;int g[12][12],f[12][12];int startx,starty;class KnightsTour {public:    bool check(int,int);    void init(vector<string>);    void dfs(int,int);int visitedPositions(vector <string>);};bool KnightsTour::check(int x,int y) {    return ( x>=0 && x < 8 && y >=0 && y < 8);}void KnightsTour::init(vector <string> board) {    for (int i = 0 ; i < n ; i++ )         for (int j = 0 ; j < n ; j++)             if (board[i][j]=='.') g[i][j] = 0;            else if (board[i][j]=='*') g[i][j] = 1;            else if (board[i][j]=='K') {                startx = i;                starty = j;            }}void KnightsTour::dfs(int x,int y) {     if (x==-1) return;    ans++;    for (int i = 0 ; i < n ; i++ )         for (int j = 0 ; j < n ; j++) {            if (!g[i][j]) {                int tmp = 0;                for (int k = 0 ; k < 8 ; k++ ) {                    int tx = i + dx[k];                    int ty = j + dy[k];                    if ( !g[tx][ty] && check(tx,ty) ) tmp++;                }                f[i][j] = tmp;            }        }    g[x][y] = 1;     int m = 100 , nx = -1 , ny = -1;    for (int i = 0 ; i < 8 ; i++) {        int tx = x + dx[i];        int ty = y + dy[i];        if ( check(tx,ty) && g[tx][ty]==0 && m > f[tx][ty] ) {            m = f[tx][ty];            nx = tx; ny =ty;                }    }    dfs(nx,ny);}int KnightsTour::visitedPositions(vector <string> board) {    n = (int)board.size();    init(board);ans = 0;    dfs(startx,starty);    return ans;}

500:

/* * Author:  Praesidio * Created Time:  2014-05-18 2:01:58 * File Name: srm447500.cpp */#include <cstdio>#include <iostream>#include <algorithm>#include <cstring>#include <vector>using namespace std;#define For(i , n) for(int i = 0 ; i < (n) ; ++i)#define Sz(x)  (int)((x).size())typedef long long lint ;const int maxint = -1u>>2 ;const double eps = 1e-6 ;struct Graph{    int g[50][50];    int n,m;    int match[50];    bool chk[50];    Graph(int _n ,int _m){        n = _n;        m = _m;        memset(g,0,sizeof(g));        memset(match,-1,sizeof(match));        memset(chk,0,sizeof(chk));    }    bool dfs( int p )    {        for (int i = 0 ; i < m ; i++) {            if (g[p][i] && !chk[i]) {                chk[i] = true;                if (match[i]==-1 || dfs(match[i] )) {                    match[i] = p;                    return true;                }            }        }        return false;    }    int KM()    {        int ans = 0;        for (int i = 0 ; i < n ; i++) {            memset(chk,0,sizeof(chk));            if (dfs(i)) ans++;        }        return ans;    }};class PeopleYouMayKnow{public:int maximalScore(vector <string> friends, int person1, int person2){    int ans = 0;    bool vis[50];    memset(vis,0,sizeof(vis));    for (int i = 0 ; i < (int)friends.size() ; i++) {        if ( i != person1 && i !=person2 )             if (friends[i][person1]=='Y' && friends[i][person2]=='Y') {                vis[i] = true;                ans++;            }    }    vector <int> left,right;    for (int i = 0 ; i < Sz(friends) ; i++ )         if (friends[i][person1] =='Y' && !vis[i])             left.push_back(i);    for (int i = 0 ; i < Sz(friends) ; i++ )         if (friends[i][person2] == 'Y' && !vis[i])             right.push_back(i);    Graph g( Sz(left) , Sz(right) );     for (int i = 0 ; i < Sz(left) ; i++ )         for (int j = 0 ; j < Sz(right) ; j++)             if (friends[left[i]][right[j]] == 'Y' )                 g.g[i][j] = 1;    ans += g.KM();   return int(ans) ;}};