Infix_to_Prefix

prefix.cpp

# include <stdio.h>
# include <iostream>
# include <string.h>
# define MAX 20

using namespace std;


int top=-1;
char stack[MAX];

void reverse(char array[30])
{
    int i,j;
	char temp[100];
	for (i=strlen(array)-1,j=0;i+1!=0;--i,++j) {
		temp[j]=array[i];
	}
	temp[j]='\0';
	strcpy(array,temp);

}
int isOperator(char symbol) {
	switch(symbol) {
		case '+':
		        case '-':
		        case '*':
		        case '/':
		        case '^':
		        case '$':
		        case '&':
		        case '(':
		        case ')':
		        return 1;
		break;
		default:
		        return 0;
	}
}
char pop() {
	char a;
	a=stack[top];
	top--;
	return a;
}
//----------------------------------
void push(char symbol) {
	top++;
	stack[top]=symbol;
}
//------------------------------------------
int prcd(char symbol) 
{
    	switch(symbol) {
		case '+':
		        case '-':
		        return 2;
		break;
		case '*':
		        case '/':
		        return 4;
		break;
		case '$':
		        case '^':
		        return 6;
		break;
		case '#':
		        case '(':
		        case ')':
		        return 1;
		break;
	}
}
//--------
void infixtoprefix(char infix[20],char prefix[20]) {
	int i,j=0;
	char symbol;
	push('#'); // or stack[++k]='#'
	reverse(infix);
	cout << "After reverse the Infix expression : " << infix <<endl;
	for (i=0;i<strlen(infix);i++) {
		symbol=infix[i];
		if (isOperator(symbol)==0) {
			prefix[j]=symbol;
			j++;
		} else {
			if (symbol==')') {
				push(symbol);
			} else if(symbol == '(') {
				while (stack[top]!=')') {
					prefix[j]=pop();
					j++;
				}
				pop();
			} else {
				if (prcd(stack[top])<=prcd(symbol)) {
					push(symbol);
				} else {
					while(prcd(stack[top])>=prcd(symbol)) {
						prefix[j]=pop();
						j++;
					}
					push(symbol);
				}
				//end for else
			}
		}
		//end for else
	}
	//end for for
	while (stack[top]!='#') {
		prefix[j]=pop();
		j++;
	}
	prefix[j]='\0';
}
////--------------------------------------------------------

main()
{
	char infix[20],prefix[20],temp;
	printf("Enter infix operation: ");
	cin >> infix;
	infixtoprefix(infix,prefix);
	reverse(prefix);
    cout<<prefix ;
}
//--------------------------------------------------------

this code might has some compilation error on different range of compiler limitation , please feel free to reply if you have any touble 👍