Hdu 4462 Scaring the Birds (enumeration subset)

Title Address: http://acm.hdu.edu.cn/showproblem.php?pid=4462

Idea: There is a pit. Where the scarecrow can be placed without covering; When k==n*n, the answer is 0.

#include <cstdio> #include <vector> #include <cstring> #include <iostream> #include < algorithm>using namespace Std;const int maxn=55;const int inf=0x3f3f3f3f;struct node{int x, y;}; int r[15]; Node p[15];int ans,n,k;vector<int> pick;int v[maxn][maxn];void Find () {for (Int. a=1; a<=n; a++) {for        (int b=1; b<=n; b++)            {if (v[a][b]) continue;            int flag=0;                for (int i=0; i<pick.size (); i++) {int p=pick[i];                    if (ABS (a-p[p].x) +abs (B-P[P].Y) <=r[p]) {flag=1;                Break        }} if (!flag) return;    }} int tmp=pick.size (); Ans=min (ans,tmp);}        int main () {while (scanf ("%d", &n) ==1&&n) {ans=inf;        scanf ("%d", &k);        memset (v,0,sizeof (v));            for (int i=0; i<k; i++) {scanf ("%d%d", &p[i].x,&p[i].y); V[p[I].x][p[i].y]=1;          } for (int i=0; i<k; i++) scanf ("%d", &r[i]);            if (k==n*n) {printf ("0\n");        Continue } for (int s=0; s< (1<<k);            s++) {pick.clear ();            for (int i=0; i<k; i++) if (s& (1<<i)) pick.push_back (i);        if (Pick.size () <ans) Find ();        } if (Ans==inf) printf (" -1\n");    else printf ("%d\n", ans); } return 0;}

Hdu 4462 Scaring the Birds (enumeration subset)