ZOJ 3645 BiliBili

高斯消元，注意-0.00

#include<iostream>#include<vector>#include<algorithm>#include<cstdio>#include<queue>#include<stack>#include<string>#include<map>#include<set>#include<cmath>#include<cassert>#include<cstring>#include<iomanip>using namespace std;#ifdef _WIN32#define i64 __int64#define out64 "%I64d\n"#define in64 "%I64d"#else#define i64 long long#define out64 "%lld\n"#define in64 "%lld"#endif/************ for topcoder by zz1215 *******************/#define FOR(i,a,b)      for( int i = (a) ; i <= (b) ; i ++)#define FFF(i,a)        for( int i = 0 ; i < (a) ; i ++)#define FFD(i,a,b)      for( int i = (a) ; i >= (b) ; i --)#define S64(a)          scanf(in64,&a)#define SS(a)           scanf("%d",&a)#define LL(a)           ((a)<<1)#define RR(a)           (((a)<<1)+1)#define pb              push_back#define CL(Q)           while(!Q.empty())Q.pop()#define MM(name,what)   memset(name,what,sizeof(name))#define MC(a,b)memcpy(a,b,sizeof(b))#define MAX(a,b)        ((a)>(b)?(a):(b))#define MIN(a,b)        ((a)<(b)?(a):(b))#define read            freopen("in.txt","r",stdin)#define write           freopen("out.txt","w",stdout)const int inf = 0x3f3f3f3f;const i64 inf64 = 0x3f3f3f3f3f3f3f3fLL;const double oo = 10e9;const double eps = 10e-9;const double pi = acos(-1.0);const int maxn = 13;double a[maxn][maxn];double d[maxn];double x[maxn];void init(){double add=0.0;for(int i=0;i<=10;i++){add+=a[11][i]*a[11][i];}add-=d[11];for(int i=0;i<=10;i++){d[i]+=add;for(int j=0;j<=10;j++){d[i]-=a[i][j]*a[i][j];a[i][j]*=-2.0;a[i][j]+=2.0*a[11][j];}}return ;}int find(int now,int y){int re=-1;double temp = 0.0;for(int i=now;i<=10;i++){if(fabs(a[i][y])>fabs(temp)+eps){temp = a[i][y];re = i;}}return re;}void start(){init();int now,y,temp;double t2;for(now=0,y=0;y<=10;y++){temp = find(now,y);if(temp==-1){ continue;}for(int i=y;i<=10;i++){swap(a[now][i],a[temp][i]);}swap(d[now],d[temp]);for(int i=now+1;i<=10;i++){t2 = -a[i][y]/a[now][y];a[i][y]=0.0;d[i]+=d[now]*t2;for(int j=y+1;j<=10;j++){a[i][j]+=a[now][j]*t2;}}now++;}for(int i=10;i>=0;i--){t2=d[i];for(int j=i+1;j<=10;j++){t2-=a[i][j]*x[j];}x[i]=t2/a[i][i];}return ;}int main(){int T;cin>>T;while(T--){for(int i=0;i<=11;i++){for(int j=0;j<11;j++){cin>>a[i][j];}cin>>d[i];d[i]*=d[i];}start();for(int i=0;i<10;i++){if(abs(x[i])<eps){x[i]=0.0;}printf("%.2lf ",x[i]);}if(abs(x[10])<eps){x[10]=0.0;}printf("%.2lf\n",x[10]);}return 0;}