高斯消去法_解线性方程组的直接解法

标签：计算方法实验

#include <stdio.h>const int maxn = 15 + 1;double a[maxn][maxn], b[maxn];int main(){    int n;    freopen("gauss.txt", "r", stdin);  //读入数据    scanf("%d", &n);    for(int i = 1; i <= n; i++)    {        for(int j = 1; j <= n; j++)  scanf("%lf", &a[i][j]);        scanf("%lf", &b[i]);    }    for(int k = 1; k <= n - 1; k++)  //消元过程        for(int i = k + 1; i <= n; i++)        {            double Mik = a[i][k] / a[k][k];            for(int j = k + 1; j <= n; j++)  a[i][j] -= Mik * a[k][j];            b[i] -= Mik * b[k];        }    b[n] /= a[n][n];  //回代过程    for(int i = n - 1; i >= 1; i--)    {        double sum = 0;        for(int j = i + 1; j <= n; j++)  sum += a[i][j] * b[j];        b[i] = (b[i] - sum) / a[i][i];    }    for(int i = 1; i <= n; i++)  printf("x%d = %f\n", i, b[i]);  //小优化b[]->x[]    return 0;}

数据文件

实验结果