bzoj 4004 向量拟阵
题解RT.
eps = 1e-10 WrongAnswer
eps = 1e-5 Accepted
1 /************************************************************** 2 Problem: 4004 3 User: idy002 4 Language: C++ 5 Result: Accepted 6 Time:516 ms 7 Memory:2844 kb 8 ****************************************************************/ 9 10 #include <cstdio> 11 #include <cstring> 12 #include <algorithm> 13 #define eps 1e-5 14 #define N 510 15 using namespace std; 16 17 int n, m; 18 double aa[N][N]; 19 int cost[N]; 20 int vid[N]; 21 int kid[N]; 22 23 int sg( double x ) { 24 return (x>-eps)-(x<eps); 25 } 26 bool cmp( int a, int b ) { return cost[a]<cost[b]; } 27 bool join( int id ) { 28 for( int i=1; i<=m; i++ ) { 29 if( sg(aa[id][i])==0 ) continue; 30 if( kid[i]==0 ) { 31 kid[i]=id; 32 return true; 33 } 34 int uid = kid[i]; 35 double k = aa[id][i]/aa[uid][i]; 36 for( int j=i; j<=m; j++ ) 37 aa[id][j] -= k*aa[uid][j]; 38 } 39 return false; 40 } 41 int main() { 42 scanf( "%d%d", &n, &m ); 43 for( int i=1; i<=n; i++ ) 44 for( int j=1; j<=m; j++ ) 45 scanf( "%lf", &aa[i][j] ); 46 for( int i=1; i<=n; i++ ) 47 scanf( "%d", cost+i ); 48 for( int i=1; i<=n; i++ ) 49 vid[i] = i; 50 sort( vid+1, vid+1+n, cmp ); 51 memset( kid, 0, sizeof(kid) ); 52 int cnt=0, ans=0; 53 for( int i=1; i<=n; i++ ) { 54 int id = vid[i]; 55 if( join(id) ) { 56 cnt++; 57 ans+=cost[id]; 58 } 59 } 60 printf( "%d %d\n", cnt, ans ); 61 }
