# Transpose Matrix in Algol68

Published on 06 February 2023 (Updated: 06 February 2023)

Welcome to the Transpose Matrix in Algol68 page! Here, you'll find the source code for this program as well as a description of how the program works.

## Current Solution

``````MODE PARSEINT_RESULT = STRUCT(BOOL valid, INT value, STRING leftover);
MODE PARSEINTLIST_RESULT = STRUCT(BOOL valid, REF []INT values);

PROC parse int = (REF STRING s) PARSEINT_RESULT:
(
BOOL valid := FALSE;
REAL r := 0.0;
INT n := 0;
STRING leftover;

# Associate string with a file #
FILE f;
associate(f, s);

# On end of input, exit if valid number not seen. Otherwise ignore it #
on logical file end(f, (REF FILE dummy) BOOL:
(
IF NOT valid THEN done FI;
TRUE
)
);

# Exit if value error #
on value error(f, (REF FILE dummy) BOOL: done);

# Convert string to real number #
get(f, r);

# If real number is in range of an integer, convert to integer. Indicate integer is valid if same as real #
IF ABS r <= max int
THEN
n := ENTIER(r);
valid := (n = r)
FI;

# Get leftover string #
get(f, leftover);

done:
close(f);
PARSEINT_RESULT(valid, n, leftover)
);

PROC count list items = (STRING s) INT:
(
INT count := 1;
FOR k TO UPB s
DO
IF s[k] = ","
THEN
count +:= 1
FI
OD;

count
);

PROC parse int list = (REF STRING s) PARSEINTLIST_RESULT:
(
BOOL valid := FALSE;
STRING leftover := s;
INT num list items = count list items(s);
HEAP [num list items]INT values;

# Repeat while valid value #
FOR k TO num list items
DO
# Get next integer value and update leftover string #
PARSEINT_RESULT result = parse int(leftover);
valid := valid OF result;
leftover := leftover OF result;

# Append the integer value to list #
values[k] := value OF result;

# Do nothing if end of string #
IF leftover = ""
THEN
SKIP
# Skip comma if leftover string starts with comma #
ELIF leftover = ","
THEN
leftover := leftover[2:]
# Otherwise indicate invalid #
ELSE
valid := FALSE
FI
UNTIL NOT valid
OD;

PARSEINTLIST_RESULT(valid, values)
);

PROC usage = VOID: printf((\$gl\$, "Usage: please enter the dimension of the matrix and the serialized matrix"));

# Convert list of values to a matrix #
PROC convert to matrix = (REF []INT values, INT num rows, INT num cols) REF [, ]INT:
(
HEAP [num rows, num cols]INT matrix;
INT count := 0;
FOR i TO num rows
DO
FOR j TO num cols
DO
count +:= 1;
matrix[i, j] := values[count]
OD
OD;

matrix
);

# Return a transposed version of a matrix #
PROC transpose matrix = (REF [, ]INT matrix) REF [, ]INT:
(
# Use built-in transpose operator #
TRNSP matrix
);

# Show matrix as a list of comma-separated values #
PROC show matrix as list = (REF [, ]INT matrix) VOID:
(
INT num rows = 1 UPB matrix;
INT num cols = 2 UPB matrix;
FOR i TO num rows
DO
FOR j TO num cols
DO
IF i > 1 OR j > 1
THEN
print(", ")
FI;

print(whole(matrix[i, j], 0))
OD
OD;

print(newline)
);

# Parse 1st command-line argument #
STRING s := argv(4);
PARSEINT_RESULT result := parse int(s);
INT num cols := value OF result;
IF NOT valid OF result OR num cols < 1
THEN
usage;
stop
FI;

# Parse 2nd command-line argument #
s := argv(5);
result := parse int(s);
INT num rows := value OF result;
IF NOT valid OF result OR num rows < 1
THEN
usage;
stop
FI;

# Parse 3rd command-line argument and make sure that it is the product #
# of the number of rows and columns #
s := argv(6);
PARSEINTLIST_RESULT list result := parse int list(s);
REF []INT values := values OF list result;
INT num values := UPB values;
IF NOT valid OF list result OR num values /= num rows * num cols
THEN
usage;
stop
FI;

# Convert values to matrix #
REF [, ]INT matrix := convert to matrix(values, num rows, num cols);

# Transpose matrix #
REF [, ]INT matrix t := transpose matrix(matrix);

# Show transposed matrix as a list #
show matrix as list(matrix t)

``````

Transpose Matrix in Algol68 was written by:

• rzuckerm

If you see anything you'd like to change or update, please consider contributing.

## How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

## How to Run the Solution

No 'How to Run the Solution' section available. Please consider contributing.