2.4 Evaluation of Postfix expression

/*
Input  :
       Enter the postfix expression 84+

Output :
       The final answer is 12

Assumptions
-> Evaluation of only +,-,* and / will take place.
-> Input expression must be single digit operands.
*/
#include<stdio.h>
#include<conio.h>
#define Stack_Size 50
int stack[Stack_Size],top=-1;
void Push(int element){
    if(top == Stack_Size-1){
        printf("\nStack is full");
    }
    else
        stack[++top]=element;
}
int Pop(){
    int Poped_value = stack[top];
    stack[top--]=0;
    return Poped_value;
}
void Solve(char operator){
    int b = Pop();
    if(operator == '+'){
        Push(Pop() + b);
    }
    else if(operator == '-'){
        Push(Pop() - b);
    }
    else if(operator == '*'){
        Push(Pop() * b);
    }
    else{
        Push(Pop() / b);
    }
}
int Evaluation(char exp[]){
    for(int i=0 ; exp[i] != '\0' ; i++){
        if(exp[i]>='0' && exp[i]<='9'){
            Push(exp[i]-'0');
        }
        else{
            Solve(exp[i]);
        }
    }
    return stack[top];
}
int main()
{
    char exp[20];
    printf("Enter the postfix expression ");
    scanf("%s",exp);
    printf("\nThe final answer is %d",Evaluation(exp));
    return 0;
}