/*--------------------------------
convert infix to postfix
--------------------------------*/
void infixToPostfix(char infix[max], char postfix[max]){
emptyStack();
int i=0,j=0;
while(infix[i]!='\0'){
if(isOperator(infix[i])!=1){ // if is operand
postfix[j++]=infix[i];
}else if(infix[i]== '(')
push(infix[i]);
else if(infix[i]==')'){
while(stack[top]!='(')
postfix[j++]=pop();
top--;
}else{
while(top!=-1 && prcd(infix[i])<=prcd(stack[top]))
postfix[j++]=pop();
push(infix[i]);
}
i++;
}
while(top!=-1)
if(stack[top]!=')' || stack[top]!='(')
postfix[j++]=pop();
else top--;
postfix[j]='\0';
}
void postfix(char *infix,char *result)
{
int i=0,under,outpos=0;
char topsymb='+',symb;
p.top=-1;
while(infix[i]!='\0')
{
symb=infix[i++];
if(isoperand(symb)==1)
result[outpos++]=symb;
else
{
pop(&p,&topsymb,&under);
while(under==0 && prcd(topsymb,symb))
{
result[outpos++]=topsymb;
pop(&p,&topsymb,&under);
}
if(under==0)
push(&p,topsymb);
if(under==1 || (symb!=')'))
push(&p,symb);
else
pop(&p,&topsymb,&under);
}
}
while(empty(&p)!=1)
{
pop(&p,&topsymb,&under);
result[outpos++]=topsymb;
}
result[outpos]='\0';
}
//Infix to Postfix conversion
void posfix(char infix[], char postr[]) {
int position, und;
int outpos = 0;
char topsymb = '+';
char symbol;
OPERANDSTACK opstk;
opstk.top = -1;
for (position = 0; (symbol = infix[position]) != '\0'; position++) {
if (isOperand(symbol))
{
postr[outpos++] = symbol;
} else {
popAndTest(&opstk, &topsymb, &und);
while (!und && prcd(topsymb, symbol)) {
postr[outpos++] = topsymb;
popAndTest(&opstk, &topsymb, &und);
}
if (!und) {
push(&opstk, topsymb);
}
if (und || (symbol != ')')) {
push(&opstk, symbol);
} else {
topsymb = pop(&opstk);
}
}
}
while (!isEmpty(&opstk)) {
postr[outpos++] = pop(&opstk);
}
postr[outpos] = '\0';
return;
}
inline void convertip(char infix[],char postfix[])
{
int i,symbol,j=0;
stack[++top]='#';
for(i=0;i<strlen(infix);i++)
{
symbol=infix[i];
if(isoperator(symbol)==0)
{
postfix[j]=symbol;
j++;
}
else{
if(symbol=='(')push(symbol);
else if(symbol==')')
{
while(stack[top]!='(')
{
postfix[j]=pop();
j++;
}
pop();//pop out (.
}
else{
if(prcd(symbol)>prcd(stack[top]))
push(symbol);
else{
while(prcd(symbol)<=prcd(stack[top]))
{
postfix[j]=pop();
j++;
}
push(symbol);
}//end of else.
}//end of else.
}//end of else.
}//end of for.
while(stack[top]!='#')
{
postfix[j]=pop();
j++;
}
postfix[j]='\0';//null terminate string.
}
//--------------------------------------------------------
void infixtoprefix(char infix[20],char prefix[20])
{
int i,j=0;
char symbol;
stack[++top]='#';
reverse(infix);
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';
}
void convert(char infix[size],char postfix[size])
{
int i,j=0;
char ch,op;
struct stack s;
s.top=-1;
for(i=0; infix[i]!='\0'; i++)
{
// display(&s);
ch=infix[i];
if(isopnd(ch)==1)
{
postfix[j]=ch;
j++;
}
else if(ch=='(')
{
push2(&s,ch);
}
else if(ch==')')
{
char k=pop2(&s);
while(k!='(')
{
postfix[j]=k;
j++;
k=pop2(&s);
}
//pop(&s);
}
else
{
while(!isempty(s))
{
//result=prcd(ch,s.arr[s.top]);
if(prcd(s.arr[s.top],ch)||ch=='(')
break;
op=pop2(&s);
postfix[j]=op;
j++;
}
push2(&s,ch);
}
}
while(!isempty(s))
{
op=pop2(&s);
postfix[j]=op;
j++;
}
postfix[j]='\0';
}
void convert(stack *s,char infx_str[])
{
char pstfx_str[30];
int i,j;
char z;
for(i=0,j=0;infx_str[i]!='\0';i++)
{
if(infx_str[i]>='0' && infx_str[i]<='9' || infx_str[i]>='a' && infx_str[i]<='b')
pstfx_str[j++]=infx_str[i];
else
{
switch(infx_str[i])
{
case '(':
push(s,infx_str[i]);
break;
case ')':
do{
z=pop(s);
if(z!='(')
pstfx_str[j++]=z;
}while(z!='(');
break;
default:
while(!isempty(s) && prcd(peek(s))>=prcd(infx_str[i]))
pstfx_str[j++]=pop(s);
push(s,infx_str[i]);
}
}
}
while(!isempty(s))
pstfx_str[j++]=pop(s);
pstfx_str[j]='\0';
printf("\npostfix string is ");
for(i=0;pstfx_str[i]!='\0';i++)
printf("%c",pstfx_str[i]);
//return pstfx_str;
}
/*To Covert Infix To Prefix*/
void intopre(char str1[],char pre[])
{
STK s1;
int len,flag;
len=strlen(str1);
int check=0,cnt=len-1,pos=0;
char elem;
while(cnt>=0) /*while condition*/
{
flag=0;
if(isoperand(str1[cnt])) /*Checking for Operand*/
{
printf("%c",str1[cnt]);
cnt--;
pos++;
}
else
{
check=prcd(str1[cnt]);
while(check==false)
{
pre[pos]=str1[cnt];
flag=1;
pos++;
cnt--;
}
if(flag==0)
{
elem=pop(&s1);
printf("%c",elem);
}
}
}
}
void convert(char infix[50],char prefix[50])
{
char temp[50],out[50];
int i,j;
struct stack *st=(struct stack*)malloc(sizeof(struct stack));
(*st).tos=-1;
//reverse the infix expression
for(i=strlen(infix)-1,j=0;i>=0;i--,j++)
{
temp[j]=infix[i];
}
temp[j]='\0';
printf("\nThe temp expression is: %s\n",temp);
for(i=0,j=0;temp[i]!='\0';i++)
{
/*if temp[i] is an operand write it to out[j]
if it is an operator(op) and stack is empty, push it onto stack and if stack is not empty , pop from stack
and compare the popped element and operator(op) precedence .if the precedence of popped operator is
greater than that of the operator(op) write popped opearator into out[j] otherwise push operator(op)
onto the stack. repeat the process
*/
if(isopnd(temp[i]))
{
out[j]=temp[i];
j++;
}
else if(temp[i]==')')
{
push2(st,temp[i]);
}
else if(temp[i]=='(')
{
char k=pop2(st);
while(k!=')')
{
out[j]=k;
j++;
k=pop2(st);
}
pop2(st);
}
else
{
char op1;
int flag=0;
while(1)
{
op1=temp[i];
if(isempty((st)))
{
push2(st,op1);
flag=1;
break;
}
else
{
char op2=pop2(st);
if(prcd(op1,op2)||op2=='(') //prcd op1>op2
{
push2(st,op2);
break;
}
else
{
out[j]=op2;
j++;
}
}
}
if(flag==0)
push2(st,op1);
}
}
while(!isempty(st))
{
printf("in");
out[j]=pop2(st);
j++;
}
out[j]='\0';
//printf("\nThe output expression is: %s\n",out);
//reverse the output string
for(i=strlen(out)-1,j=0;i>=0;i--,j++)
{
prefix[j]=out[i];
}
prefix[j]='\0';
return;
}
