大家帮我看看这段程序有没有错,谢谢!

只看该作者 · 发表于 2004-4-14 20:56:00

程序如下,是用来解线性方程的,用的是高斯赛德乐迭代法做的在算三个未知量的时是和答案一致的,四个未知量就有出入,做六个未知量就出错了. 谁能告诉我错在哪里了,是题错还是程序错了. 刚开始学,不足之处请指教。 #include #include #define NN 50 void main() { cout.setf(ios::fixed,ios::floatfield); cout<2 `( p" H' l2 I. Y" u int i,j,k; double e,c,T,r; //double x[NN],A[NN][NN],B[NN]; //题目如下：任选一个 //double x[NN]={0,0,0,0},A[NN][NN]={{0,0,0,0},{0,10,-2,-1},{0,-2,10,-1},{0,-1,-2,5}},B[NN]={0,3,15,10}; double x[NN]={0,0,0,0},A[NN][NN]={{0,0,0,0},{0,10,-1,-2},{0,-1,10,-2},{0,-1,-1,5}},B[NN]={0,7.2,8.3,4.2}; //double x[NN]={0,0,0,0,0},A[NN][NN]={{0,0,0,0,0},{0,-5,1,1,2},{0,2,8,1,3},{0,1,-2,-4,-1},{0,-1,3,2,7}},B[NN]={0,-2,-6,6,12}; //double x[NN]={0,0,0,0,0,0,0},A[NN][NN]={{0,0,0,0,0,0,0},{0,1,-1,0,-1,0,0},{0,2,4,-1,0,-1,0},{0,4,-1,4,-1,0,-1},{0,8,0,-1,4,-1,0},{0,12,-1,0,-1,4,-1},{0,16,0,-1,0,-1,4}},B[NN]={0,0,5,-2,5,-2,6}; //double x[NN]={0,0,0,0,0},A[NN][NN]={{0,0,0,0,0},{0,1,0.333,1.5,-0.333},{0,-2.01,1.45,0.50,2.95},{0,4.32,-1.95,0.007,2.08},{0,5.11,-4.00,3.33,-1.11}},B[NN]={0,3.00,2.62,0.130,3.77}; //double x[NN]={0,0,0,0},A[NN][NN]={{0,0,0,0},{0,10,3,1},{0,2,-10,3},{0,1,3,10}},B[NN]={0,14,-5,14}; int N; cout<<"请输入N值:"; cin>>N; cout<; R0 c4 ?$ \' ?, z cin>>e; /*cout<2 r( z# ^# f) M0 ? for(i=1;i<=N;i++) for(j=1;j<=N;j++) { cin>>A[j]; 2 j5 e5 N7 [ n }8 p, B7 m1 q+ l8 k5 [) y cout<& b/ e8 p" f9 h# d% C for(i=1;i<=N;i++)2 S$ a! \# q3 Q2 n; B: s { 4 M7 U, L5 b6 E2 L2 f, Y for(j=1;j<=N;j++) 6 r$ |7 l; {! _7 u9 N { 7 @9 C4 Q9 L/ R# X! l6 ^ cout<[j]<<' '; # \3 z" R' }; c8 K' e, w6 r6 V- W8 j ; i w+ w9 _. K( M( d" r0 W } ' k" w. S" _/ N cout<4 z1 V' Y8 `* T% ~ } - |7 l1 K t6 z- b& g5 g; T6 ~" K cout< f8 x$ H" g/ j4 v$ T; X$ k: ~ for(i=1;i<=N;i++)cin>>B; 7 A, Q* C6 `% x4 _/ Y8 f# Q6 @5 t for(i=1;i<=N;i++)cout<<<' '; % x! R% s4 j# i, _0 r cout<9 u- E1 Z9 l& p! _8 v9 v% g for(i=1;i<=N;i++)cin>>x;*/& O' Y' N$ p$ r ! B5 x' L- o. S) B, l3 g( N p //cout<<"k"<6 R( H! D( e7 S //for(i=1;i<=N;i++)cout<<"x["<" ]; J) I4 M3 ]4 a i9 d. Z r=e; 2 x4 ?/ J) J% ]5 V for(k=1;r>=e;k++)! ?; _5 m {0 f { $ f) d3 Q6 D0 s$ T r=0; - j! b" H( Z& `3 j. n i=1;' U. z; P: X+ c/ s for(i=1;i<=N;i++) * ~2 V4 i; ~3 c( D0 { { - F7 r) J) d/ n( J7 E9 [2 ]7 x4 t T=x;. Y9 M0 \* z# e8 u9 S0 U7 R c=0;" q' Z. L8 o* b for(j=1;j<=N;j++): o+ Q B" I- F1 T; j8 M { 1 ~; L7 t& q, `: X if(j!=i)c+=(A[j]*x[j]);. r# Y. X, I- _. W cout<<"第"<. s) [7 w% u& [6 X! e. E }" _# ^- m0 m, ?$ @9 r' a0 ^" v //c1=0; H6 L* p. j. o2 I1 Q: a9 ~ //for(j=1;j<=i-1;j++)c1+=(A[j]*x[j]);' @; Y: T0 L1 `& d( }2 k1 I7 w4 \9 C( J x=(B-c)/A; 3 X) N1 \, H" U$ |) w V7 [ cout<<"第"<<8 o/ d' p* s/ ~" a- G" G if((fabs(x-T))>r)r=fabs(x-T);3 U9 r: R2 W& i! z0 i# v cout<<"第"<% H; Z3 W' l4 f; Q3 k4 l }6 l5 v' E) ~! M, y6 l+ \ cout<- O1 \2 X) a2 U5 ~% Z( R: H& ^ //cout<<"k="<% |# N/ N( m% r/ F* d ; R2 p8 ]0 j9 l. l3 T //cout.setf(ios::fixed,ios::floatfield);+ \8 ~7 n# P8 I2 ^" b4 C for(i=1;i<=N;i++)cout<<"k="<<<' ';//<7 N, l" ]0 A) U7 P- A* O , f$ J+ P' P$ P3 k+ u2 f* { }cout<: V5 d- o3 N" N5 ]2 h- X5 i1 B : q7 r1 O, V, n5 E6 T}