hdu 4462 Scaring the Birds # 暴力枚举（状压）

其实是枚举的水题，也是当年regional的签到题，然而我卡了一个小时，啊啊啊啊啊啊啊

暴力枚举，可以用状压表示状态就是2^10，其他也没什么了

#include <iostream>#include <cstdio>#include <cstring>#include <queue>#include <vector>#include <algorithm>#include <cmath>using namespace std;struct node{    int x , y , r ;    //node(int x , int y , int r):x(x) ,y(y),r(r){}    bool operator < ( const node & k ) const {        return r < k.r ;    }};node save[20] , temp[20];bool pic[200][200] ;int n , res;int get_bit(int x){    int ans = 0 ;    while(x){        if(x & 1) ans ++ ;        x >>= 1 ;    }    return ans ;}void work(int x){    int bit = get_bit(x) ;    if(bit >= res) return ;    int pos = 0 , tpos = 0 ;    while(x){        if(x & 1) temp[pos++] = save[tpos] ;        x >>= 1 , tpos ++ ;    }    int k ;    for(int i = 1 ; i <= n ; i ++ ){        for(int j = 1 ; j <= n ; j ++ ){            if( pic[i][j] ) continue ;            for(k = 0 ; k < pos ; k ++ ){                //cout << temp[i].x << " " << temp[i].y << "     " ;                if( fabs(i - temp[k].x )+ fabs(j - temp[k].y)  <= temp[k].r )  break ;            }            //cout << k << endl ;            if( k >= pos ) return ;        }    }    //cout << 25423;    res = bit ;}int main(){    int point , a , b , r;    while( ~ scanf("%d" , &n) && n ){        scanf("%d" , &point) ;memset(pic , 0 , sizeof(pic)) ;        for(int i = 0 ; i < point ; i ++){            scanf("%d %d" , &a , &b);            save[i].x = a , save[i].y = b ;            pic[a][b] = true ;        }        for(int i = 0 ; i < point ; i ++ ){            scanf("%d" , &r) ;            save[i].r = r ;        }        res = 100 ;        work( (1<<point)- 1 ) ;        if(res == 100 ){ printf("-1\n") ; continue ; }        for(int i = 1 ; i < (1<<(point)) ; i = i<<1 )work(i) ;        for(int i = 0 ; i < (1<<(point)) ; i ++ )    work(i) ;        printf("%d\n" , res ) ;    }    return 0 ;}