Seidel迭代法

PS:e为误差值，自己设定

#include<stdio.h>
#include<math.h>
#define N 3
#define col 3//列数
#define row 3//行数
void print(double a[row][col]) {for (int i = 0; i < row; i++)//找到最大主元，记录行号和列号{for (int j = 0; j < col; j++){printf("%f  ", a[i][j]);}printf("\n");}printf("\n");
}void printXY(double XY[N]) {for (int i = 0; i < N; i++){printf("%f  ", XY[i]);}printf("\n\n");
}void Seidel(double X[N],double b[N], double a[N][N],double e)
{double p;for (int i = 1; i <=N; i++){X[i-1] = 0;}do {p = 0;for (int i = 1; i <= N; i++){double t = X[i-1];double sum = 0;for (int j = 1; j <= N; j++){if (j == i)continue;sum += a[i-1][j-1] * X[j-1];}X[i - 1] = (b[i - 1] - sum) / a[i - 1][i - 1];if (fabs(X[i - 1] - t) > p)p = fabs(X[i-1] - p);}} while (p>e);
}int main()
{double a[N][N] = {	{ 4,3,0},{ 3,4,-1 },{ 0,-1,4 },}, b[N] = {24,30,-24}, X[N] = { 0 },e=0;Seidel(X,b,a,e);printXY(X);getchar();
}