IHYPRESS PROGRAMMING

Tutorials and C programs with code and output for beginners

<09.04>

/* Multiplication of two matrices */ #include <stdio.h> #define M 3 /* n of rows in first matrix */ #define N 4 /* n of cols in first and of rows in 2nd */ #define P 5 /* n of cols on 2nd matrix */ void multmatrix (int a[M][N], int b[N][P], int c[M][P]) { int i,j,k; for (i=0; i<M; ++i) for (j=0; j<P; ++j) { c[i][j]=0.0; for (k=0; k<N; ++k) c[i][j] = c[i][j] + a[i][k] * b[k][j]; } } int main (void) { int i,j; int mat1[M][N]={{1,2,2,2},{2,-3,6,4},{8,1,0,-3}}; int mat2[N][P]={{1,1,1,0,3},{2,3,1,6,2},{1,-1,-1,8,3},{0,1,2,3,4}}; int matprod[M][P]; /* do the multiplication */ multmatrix (mat1, mat2, matprod); /* display the resulting matrix */ for (i=0; i<M; ++i) { for (j=0; j<P; ++j) printf ("%4d ", matprod[i][j]); printf ("\n"); } return (0); }

7 7 5 34 21 2 -9 1 42 34 10 8 3 -3 14