Write a prefix method to accept an infix string and create the prefix form of that string, assuming that the string is read from right to left and that the prefix string is created from right to left.
(Solved Homework): Write a prefix method to accept an infix string and create the prefix form of that string, assuming that the strin…
Expert Answer
Don't use plagiarized sources. Get Your Custom Essay on
(Solved Homework): Write a prefix method to accept an infix string and create the prefix form of that string, assuming that the strin…
Get an essay WRITTEN FOR YOU, Plagiarism free, and by an EXPERT!
#include<stdio.h>
#include<conio.h>
#include<string.h>
#define MAX 20
char stack[MAX];
int top = -1;
char pop();
void push(char item);
int precedence(char symbol)
{
switch(symbol)
{
case ‘+’:
case ‘-‘:
return 2;
case ‘*’:
case ‘/’:
return 4;
case ‘^’:
case ‘$’:
return 6;
case ‘(‘:
case ‘)’:
case ‘#’:
return 1;
}
}
int isoperator(char symbol)
{
switch(symbol)
{
case ‘+’:
case ‘-‘:
case ‘*’:
case ‘/’:
case ‘^’:
case ‘$’:
case ‘(‘:
case ‘)’:
return 1;
default:
return 0;
}
}
void convert_infix_to_prefix(char infix[],char prefix[])
{
int i,symbol,j=0;
char test[MAX];
infix=strrev(infix);
stack[++top]=’#’;
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();//pop out (.
}
else
{
if(precedence(symbol)>precedence(stack[top]))
{
push(symbol);
}
else
{
while(precedence(symbol)<=precedence(stack[top]))
{
prefix[j]=pop();
j++;
}
push(symbol);
}//end of else.
}//end of else.
}//end of first else.
}//end of for.
while(stack[top]!=’#’)
{
prefix[j]=pop();
j++;
}
prefix[j]=’ ’;//null terminate string.
prefix=strrev(prefix);
}
int main()
{
char infix[20],prefix[20];
clrscr();
printf(“Enter the valid infix string:n”);
gets(infix);
convert_infix_to_prefix(infix,prefix);
printf(“The corresponding prefix string is:n”);
puts(prefix);
getch();
return 0;
}
void push(char item)
{
top++;
stack[top]=item;
}
char pop()
{
char a;
a=stack[top];
top–;
return a;
}
output:
Enter the valid infix string:
A+B*C
The corresponding prefix string is:
+A*BC
