| 17 | // 高斯消元解决加法方程组模版 |
| 18 | // 需要保证变量有n个，表达式也有n个 |
| 19 | public static void gauss(int n) { |
| 20 | for (int i = 1; i <= n; i++) { |
| 21 | // 如果想严格区分矛盾、多解、唯一解，一定要这么写 |
| 22 | int max = i; |
| 23 | for (int j = 1; j <= n; j++) { |
| 24 | if (j < i && Math.abs(mat[j][j]) >= sml) { |
| 25 | continue; |
| 26 | } |
| 27 | if (Math.abs(mat[j][i]) > Math.abs(mat[max][i])) { |
| 28 | max = j; |
| 29 | } |
| 30 | } |
| 31 | swap(i, max); |
| 32 | if (Math.abs(mat[i][i]) >= sml) { |
| 33 | double tmp = mat[i][i]; |
| 34 | for (int j = i; j <= n + 1; j++) { |
| 35 | mat[i][j] /= tmp; |
| 36 | } |
| 37 | for (int j = 1; j <= n; j++) { |
| 38 | if (i != j) { |
| 39 | double rate = mat[j][i] / mat[i][i]; |
| 40 | for (int k = i; k <= n + 1; k++) { |
| 41 | mat[j][k] -= mat[i][k] * rate; |
| 42 | } |
| 43 | } |
| 44 | } |
| 45 | } |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | public static void swap(int a, int b) { |
| 50 | double[] tmp = mat[a]; |