Leetcode Clone Project

Introduction

In this Blog we will Understand how will we create a problem statement with judge0 for our leetcode clone

Algorithim for create Problem -

get all the problem related data from the req.body
get the user from the cookies and check if the user is admin or not
add checks if no user or user is not empty then resitrict them from creating a problem
Now we will loop through each refrence Solutions and get the language and the solution code
Now with the help of judge0 we will get the language id.
Check if No Language ID then simply return
Now make a submission bach for each of the test cases-with sourcecode,language_id,stdin,expected_output
Now submit the batch to judge0 and it will give a token for the submission batch
concatinate all the tokens together
submit all the tokens and then judge0 will return a submission dataset
- in Submission make a infinite loop and call judge0 api for a submission result
- if the status are in queue and processing wait for the result
- if the status is not in queue or in processing return from the loop
check for the result if not accepted the return not accepted or else
save the problem in the database
return a response to the user with the saved problem

Detail Breakdown and Structure of code and Implementation

Create a problem schema

Get the Problem Imputs

Check the User role again for Security

The Refrence-solution json input looks like

  "refrenceSolutions": {
          "JAVASCRIPT": "const fs = require('fs');\n\n// Reading input from stdin (using fs to read all input)\n
          const input = fs.readFileSync(0, 'utf-8').trim();\nconst [a, b] = input.split(' ').map(Number);\n\nconsole.log(a + b);",

          "PYTHON": "import sys\ninput_line = sys.stdin.read()\na, b = map(int, input_line.split())\nprint(a + b)",

          "JAVA": "import java.util.Scanner;\n\npublic class Main {\n public static void main(String[] args) {\n    Scanner sc = new Scanner(System.in);\n        int a = sc.nextInt();\n        int b = sc.nextInt();\n        System.out.println(a + b);\n    }\n}"
      }

From this JSON input we will destructure the language and the solution code

We will loop through the refrenceSolutions and for languageId we will get the language id for each language

for other languages language ID

http://localhost:2358/docs#statuses-and-languages-language-get-1

  [
    {
      "id": 45,
      "name": "Assembly (NASM 2.14.02)"
    },
    {
      "id": 46,
      "name": "Bash (5.0.0)"
    },
    {
      "id": 47,
      "name": "Basic (FBC 1.07.1)"
    },
    {
      "id": 48,
      "name": "C (GCC 7.4.0)"
    },
    {
      "id": 52,
      "name": "C++ (GCC 7.4.0)"
    },
    {
      "id": 49,
      "name": "C (GCC 8.3.0)"
    },
    {
      "id": 53,
      "name": "C++ (GCC 8.3.0)"
    },
    {
      "id": 50,
      "name": "C (GCC 9.2.0)"
    },
    {
      "id": 54,
      "name": "C++ (GCC 9.2.0)"
    },
    {
      "id": 51,
      "name": "C# (Mono 6.6.0.161)"
    },
    {
      "id": 55,
      "name": "Common Lisp (SBCL 2.0.0)"
    },
    {
      "id": 56,
      "name": "D (DMD 2.089.1)"
    },
    {
      "id": 57,
      "name": "Elixir (1.9.4)"
    },
    {
      "id": 58,
      "name": "Erlang (OTP 22.2)"
    },
    {
      "id": 44,
      "name": "Executable"
    },
    {
      "id": 59,
      "name": "Fortran (GFortran 9.2.0)"
    },
    {
      "id": 60,
      "name": "Go (1.13.5)"
    },
    {
      "id": 61,
      "name": "Haskell (GHC 8.8.1)"
    },
    {
      "id": 62,
      "name": "Java (OpenJDK 13.0.1)"
    },
    {
      "id": 63,
      "name": "JavaScript (Node.js 12.14.0)"
    },
    {
      "id": 64,
      "name": "Lua (5.3.5)"
    },
    {
      "id": 65,
      "name": "OCaml (4.09.0)"
    },
    {
      "id": 66,
      "name": "Octave (5.1.0)"
    },
    {
      "id": 67,
      "name": "Pascal (FPC 3.0.4)"
    },
    {
      "id": 68,
      "name": "PHP (7.4.1)"
    },
    {
      "id": 43,
      "name": "Plain Text"
    },
    {
      "id": 69,
      "name": "Prolog (GNU Prolog 1.4.5)"
    },
    {
      "id": 70,
      "name": "Python (2.7.17)"
    },
    {
      "id": 71,
      "name": "Python (3.8.1)"
    },
    {
      "id": 72,
      "name": "Ruby (2.7.0)"
    },
    {
      "id": 73,
      "name": "Rust (1.40.0)"
    },
    {
      "id": 74,
      "name": "TypeScript (3.7.4)"
    }
  ]

Check if The Language is supported or not

Make a submissions to send it to Judge0- for each testCases we are making an submission

Docs : http://localhost:2358/docs#submissions-submission-batch-post

test cases JSON

  "testcases": [
          {
              "input": "100 200",
              "output": "300"
          },
          {
              "input": "-500 -600",
              "output": "-1100"
          },
          {
              "input": "0 0",
              "output": "0"
          }
      ],

Now Submit the Batch all together to Judge0

as a return you will get TOKEN from the submission Batch
Concatinate all the tokens together
Submit the tokens to Judge0 to get a response
- Check for the status - don’t return until its in Queue or in Processing

Status id for the submissions

  [
    {
      "id": 1,
      "description": "In Queue"
    },
    {
      "id": 2,
      "description": "Processing"
    },
    {
      "id": 3,
      "description": "Accepted"
    },
    {
      "id": 4,
      "description": "Wrong Answer"
    },
    {
      "id": 5,
      "description": "Time Limit Exceeded"
    },
    {
      "id": 6,
      "description": "Compilation Error"
    },
    {
      "id": 7,
      "description": "Runtime Error (SIGSEGV)"
    },
    {
      "id": 8,
      "description": "Runtime Error (SIGXFSZ)"
    },
    {
      "id": 9,
      "description": "Runtime Error (SIGFPE)"
    },
    {
      "id": 10,
      "description": "Runtime Error (SIGABRT)"
    },
    {
      "id": 11,
      "description": "Runtime Error (NZEC)"
    },
    {
      "id": 12,
      "description": "Runtime Error (Other)"
    },
    {
      "id": 13,
      "description": "Internal Error"
    },
    {
      "id": 14,
      "description": "Exec Format Error"
    }
  ]