notes char top_chstk stackinitstack(&stack)/initialise stack *get_infix(infix)/get infix expression from user *length strlen(infix)if length /if strlen if infix is more than zero *push(&stack'(')strcat(infix")")length++for = <lengthi+if isdigit(infix[ ]/if current operator in infix is digit *postfix[ ++infix[ ]left else if infix[ ='(parenthesis */if current operator in infix is push(&stack'(')else if isoperator(infix[ ]/if current operator is operator *while( top_ch stacktop(&stack)if top_ch ='\ /get tos */no stack left *printf("\ninvalid infix expression\ ")exit( )else if isoperator(top_chif pred_level(top_ch>pred_level(infix[ ]postfix[ ++pop(&stack)else breakelse lovely professional university