Feat: Add solution for the externship task

[aguyran]

• Externship Task Completed
• All Tasks Passed

Approach

• Iterated over the equation and maintained character into a temporary variable token to keep track of current digits or symbols and pushed it to an array called split whenever empty space encountered(" ").
• whenever question mark encountered it can be said it is at the number at split array length as indexing is from 0 but length is total no. of elements so store it in positionOfQues
• Now we have 4 equations, ex if question mark is there in first number (D-C/B)=?
• Use the correct equation according to the positionOfQues, and use eval to solve it
• if there would be a 0 at left it would be automatically removed because its a number so we just check the length of answer with original, if they don't match 0 was on the left side or answer was not possible.
• Now if lengths match we check all the digits of the question with Answer minus the digit at ? if it matches we return position of question mark in answer otherwise -1
• Map to check test cases.