Infix to Postfix

Algorithm:

• Create a stack to operator
• Create empty postfix string named postfixStr
• Iterate expression string from start to end
  • If currentCharacter is operand then,
    >postfixStr += currentCharacter
  • Else If currentCharacter is opening bracket then,
    • stack.push(currentCharacter)
  • Else If currentCharacter is closing bracket then,
    • Pop stack and add popped character to postfixStr till we find opening bracket in stack
  • Else
    • If stack.top operator precedence is higher or equal to currentCharacter precedence then,
      • postfixStr += stack.pop
      • Repeat till previous condition not break
    • stack.push (currentCharacter)
• Return postfixStr

Latest Source Code:
Github: InfixToPostfix.java

Output:

A + B * C + D   ABC*+D+
(A + B) * (C + D)   AB+CD+*
A * B + C * D   AB*CD*+
A + B + C + D   AB+C+D+
a+b*(c^d-e)^(f+g*h)-i   abcd^e-fgh*+^*+i-