#define NN 3
void inv(double a[NN][NN])
{
int i, j, k;
double p, q;
for (k = 0; k < NN; k++) {
p = a[k][k];
a[k][k] = 1.0;
for (j = 0; j < NN; j++) a[k][j] /= p;
for (i = 0; i < NN; i++) {
if (i != k) {
q = a[i][k];
a[i][k] = 0.0;
for (j = 0; j < NN; j++) a[i][j] -= q * a[k][j];
}
}
}
}
>>307
でないっすよ