suanfa.rar_newton_newton polynomial_多项式拟合_线性插值

#include<stdio.h> #include<math.h> main() {float a[10][10],b[10],s,t,e,sum; int i,j,k,n,m; printf("The top exp is "); scanf("%d",&n); for(i=0;i<n;i++) for(j=0;j<n;j++) scanf("%f",&a[i][j]); for(i=0;i<n;i++) scanf("%f",&b[i]); scanf("%f",&e); k=0; do{t=a[k][k]; for(i=k;i<n;i++) {if(fabs(t)<fabs(a[i][k])) {t=a[i][k]; m=i; } else m=k; } if(fabs(t)<e) printf("det A = 0\n"); else {if(m!=k) {for(j=0;j<n;j++) {s=a[m][j]; a[m][j]=a[k][j]; a[k][j]=s; } s=b[m]; b[m]=b[k]; b[k]=s; } for(i=k+1;i<n;i++) for(j=k+1;j<n;j++) {a[i][k]=a[i][k]/a[k][k]; a[i][j]=a[i][j]-a[i][k]*a[k][j]; b[i]=b[i]-a[i][k]*b[k]; } } k++; }while(k<n-2); if(fabs(a[n-1][n-1])<e) printf("det A = 0\n"); else {b[n-1]=b[n-1]/a[n-1][n-1]; for(i=n-2;i>=0;i--) {sum=0; for(k=i+1;k<n;k++) {sum+=a[k][j]*b[j];} b[i]=(b[i]-sum)/a[i][i]; } } for(i=0;i<n;i++) printf("%f\n",b[i]); }