void multiplyMatrix(int a, int b, int matA[maxn][maxn], int c, int d, int matB[maxn][maxn], int matRet[maxn][maxn]) {// assert(b == c);int i, j, k;for(i = 0; i < a; ++i) {for(j = 0; j < d; ++j) {matRet[i][j] = 0;for(k = 0; k < b; ++k...