#!/usr/bin/env gawk -f

# BEGIN block: Initialize global variables and print graph header
BEGIN {
    print "digraph G {";
}

# Process each input line
{
    if (NF != 2) {
        printf("Warning: Skipping malformed line: %s\n", $0) > "/dev/stderr";
        next;
    }
    edges[$1, $2] = 1;  # Store edge as key in associative array
}

# END block: Print graph edges and footer
END {
    for (combined in edges) {
        split(combined, edge, SUBSEP);
        printf("\t\"%s\" -> \"%s\";\n", edge[1], edge[2]);
    }
    print "}";
}