cf_run

#!/bin/bash
# This script will check the directory name and then using the codeforces contest Id, and problem name, it will take the input using web scraping and then run the input and check its correctness with the output.

# Defining some colors for higlighting the output
RED='\033[0;31m'
GREEN='\033[0;032m'
ORANGE='\033[0;33m'
BLUE='\033[0;34m'
NC='\033[0m'
UNDERLINE='\e[4m'

# Checking if we have proper arguments list or not
if [ $# -ne 2 ]; then
    echo "$(basename $0): improper arguments list"
    echo "Usage: cf_run 'ouput file' 'problem name(ex. A,B...)'"
    exit -1
fi

# Assigning variables
curl=$(which curl)
programFile=$1
inputTextFile="input.txt"
tempOutputFile="temp.txt"
outputTextFile="output.txt"
neededData=""
url="https://codeforces.com/contest/$(pwd | tr '/' '\n' | tail -1)/problem/$2"

function check_error() {
    if [ $? -ne 0 ]; then
        echo -e "$(basename $0): $1"
        exit -1
    fi
}
# This function scrapes data from the web page 
function dump_webpage() {
    echo -e "\n> Fetching sample cases from ${ORANGE}$url${NC}\n"

    # Retreiving and parsing the web page data
    # STEPS to parse - 
    # 1) Replace all line breaks with '|' symbol
    # 2) Get the data between <pre></pre> -- This is where input and output is present
    # 3) Remove all the HTML tags and replace 'Output' with '=====' -- This separates TestCases and Output
    local webPageData=$(curl -L $url)
    check_error "Failure occurred while loading web pages!"

    neededData=$(echo "$webPageData" | tr '\n' '|' | grep -o 'Example.*</pre>' | sed 's/<[^>]*>/\n/g' | sed 's/Examples//g' | sed 's/Example//g' | sed 's/Input/=====/g' | sed 's/Output/=====/g' | tr -s '\n' '|')

    # Checking if the neededData variable is NULL -- This will happen if web page was not loaded correctly
    if [ -z "$neededData" ]; then
        echo -e "\n${RED}Error:${NC} Data cannot be parsed!\n${BLUE}Debug:${NC} Make sure you are in correct directory!\n"
        echo "+-----WEB PAGE DATA-----+"
        echo $webPageData
        echo "+-----+-----+-----+-----+"
        exit -1
    fi
}

# This function runs the given compiled file against the scaped test_cases
function run_test_cases() {
    echo -e "\n> Running file ${ORANGE}'$programFile'${NC} against sample test cases...\n"

    local data=$(echo -e $neededData | tr -s '=' '\n')
    local is_input=0
    local test_case=0
    while IFS= read -r data_part;
    do
        # Clearing input and output file
        [ `expr $is_input % 2` -eq 0 ] && true > $inputTextFile
        [ `expr $is_input % 2` -ne 0 ] && true > $tempOutputFile

        [ -z "$data_part" ] && continue
        if [ "$data_part" != "|" ]; then
            local lines=$(echo -e $data_part | tr '|' '\n')
            while IFS= read -r line;
            do
                [ -z "$line" ] && continue;
                if [ `expr $is_input % 2` -eq 0 ]; then 
                    echo "$line" | cat >> $inputTextFile
                else
                    echo "$line" | cat >> $tempOutputFile
                fi
            done <<< "$lines"

            # Checking each test case
            is_input=`expr $is_input + 1`
            if [ `expr $is_input % 2` -eq 0 ]; then
                test_case=`expr $test_case + 1`
                # Running against each input
                true > $outputTextFile
                ./$programFile < $inputTextFile > $outputTextFile
                check_error "Failure occurred while running output file!"
    
                # Checking diff between the files
                local diffOutput=$(diff $outputTextFile $tempOutputFile)
                local diffLines=$(echo "$diffOutput" | wc -l)
                if [ $diffLines -gt 1 ]; then
                    echo -e "--------------------\n>> Input:"
                    cat $inputTextFile
                    echo -e "--------------------\n>> Output:"
                    cat $outputTextFile
                    echo -e "--------------------\n>> Expected:"
                    cat $tempOutputFile
                    echo -e "--------------------\n"
    
                    echo -e "${RED}\u2718 Failed for test case $test_case!${NC}"
                    echo -e "--------------------\n>> Output from diff"
                    echo "$diffOutput"
                    echo -e "--------------------\n"
                    exit -1
                fi
            fi
        fi
    done <<< "$data"

    echo -e "--------------------\n>> Last Input:"
    cat $inputTextFile
    echo -e "--------------------\n>> Output:"
    cat $outputTextFile
    echo -e "--------------------\n>> Expected:"
    cat $tempOutputFile
    echo -e "--------------------\n"
    echo -e "${GREEN}\u2714 $test_case/$test_case sample test cases passed!\n${NC}"
}

#####################
#       MAIN        #
#####################
dump_webpage
run_test_cases