C Program to find the Inverse of the Matrix

#include<stdio.h> #include<math.h> float detrminant(float[][], float); void cofactors(float[][], float); void trans(float[][], float[][], float); void main() { float a[25][25], n, d; int i, j; printf("Enter the order of the matrix:\n"); scanf("%f", &n); printf("Enter the elemnts into the matrix:\n"); for (i = 0; i < n; i++) { for (j = 0; j < n; j++) { scanf("%f", &a[i][j]); } } d = detrminant(a, n); printf("\nTHE DETERMINANT IS=%2f", d); if (d == 0) printf("\nMATRIX IS NOT INVERSIBLE\n"); else cofactors(a, n); } float detrminant(float a[25][25], float k) { float s = 1, det = 0, b[25][25]; int i, j, m, n, c; if (k == 1) { return (a[0][0]); } else { det = 0; for (c = 0; c < k; c++) { m = 0; n = 0; for (i = 0; i < k; i++) { for (j = 0; j < k; j++) { b[i][j] = 0; if (i != 0 && j != c) { b[m][n] = a[i][j]; if (n < (k - 2)) n++; else { n = 0; m++; } } } } det = det + s * (a[0][c] * detrminant(b, k - 1)); s = -1 * s; } } return (det); } void cofactors(float num[25][25], float f) { float b[25][25], fac[25][25]; int p, q, m, n, i, j; for (q = 0; q < f; q++) { for (p = 0; p < f; p++) { m = 0; n = 0; for (i = 0; i < f; i++) { for (j = 0; j < f; j++) { b[i][j] = 0; if (i != q && j != p) { b[m][n] = num[i][j]; if (n < (f - 2) n++; else { n = 0; m++; } } } } fac[q][p] = pow(-1, q + p) * detrminant(b, f - 1); } } trans(num, fac, f); } void trans(float num[25][25], float fac[25][25], float r) { int i, j; float b[25][25], inv[25][25], d; for (i = 0; i < r; i++) { for (j = 0; j < r; j++) { b[i][j] = fac[j][i]; } } d = detrminant(num, r); inv[i][j] = 0; for (i = 0; i < r; i++) { for (j = 0; j < r; j++) { inv[i][j] = b[i][j] / d; } } printf("\nTHE INVERSE OF THE MATRIX:\n"); for (i = 0; i < r; i++) { for (j = 0; j < r; j++) { printf("\t%2f", inv[i][j]); } printf("\n"); } }