Evaluate Postfix Expression using Stack

[@girishkumargoyal5480]

videos are great for understand algorithms......

[@nETSETOStECH]

Thank you friend. Share with your friends also.😀

[@somalasresthasomala8974]

GREAT VIDEO, truly appreciate your efforts!

[@meitarG]

And what will happen if we don't have 2 numbers at the beginning of the array? or if we divide by zero? [5,*,2,/,0,*,+,3,-]

[@tejoram2265]

thanks you great video

[@husseindarwish8731]

Thank you for video My question How to do simulation of expression evaluation using stack?

[@ramilashraf2669]

for this [5,1,2,/,4,*,+,3,-] the output should be 4 but its showing 2

[@kishorereddy9453]

Return value should be stack[0] not stack [-1]

[@KrishnaManohar8021]

Please build the program, then we easily understand flow of the program.

[@nETSETOStECH]

Python program is also attached in Github github.com/netsetos/python_code/blob/master/eval_expression.py

[@sarveshrai4286]

if exprn is=['2','3','*','+','4'] then what will happen

[@shazznomani1368]

I think this isn't postfix expression, it should be [2, 3, *, 4, +]

[@adityajadhav879]

def eval_expression(arr): stack = [] operator = ["+", "-", "*", "/", "%"] for item in arr: if item not in operator: stack.append(int(item)) # Convert the operand to an integer else: first = int(stack.pop()) sec = int(stack.pop()) if item == "+": stack.append(sec + first) elif item == "-": stack.append(sec - first) elif item == "*": stack.append(sec * first) elif item == "/": stack.append(sec / first) elif item == "%": stack.append(sec % first) return stack[-1] A = ["7", "5", "3", "-", "2", "*", "+"] print(eval_expression(A)) "CORRECT CODE "

[@黑人問號-z3i]

....it's must have a troblem 14 2 - 3 / 7 11 * + ↑it can't run...