Slip 9_1,Slip 25_2 : Write a program to convert an infix expression of the form (a*(b+c)*((da)/b)) into its equivalent postfix notation. Consider usual precedence’s of operators. Use stack library of stack of characters using static implementation.

-

 Solution :

Header File : stack.h

#include<stdio.h>

char s[20];

int top;

void init()

{

 top=-1;

}

int isempty()

{ if(top==-1)

 return 1;

 else return 0;

}

int isfull()

{ if(top==19)

 return 1;

 else

 return 0;

}

void push(char data)

{

 if(isfull()==1)

 printf("\nStack is full ");

 else

 { top++;

 s[top]=data;

 }

}

char pop()

{ char data;

 if(isempty()==1)

 printf("\nStack is empty ");

 else

 { data=s[top];

 top--;

 return data;

 }

}

int peek()

{ return s[top];

}

Program File :

#include<stdio.h>

#include "stack.h"

int priority(char ch)

{ switch(ch)

 {

 case '(':return 0;

 case '+':

 case '-':return 1;

 case '*':

 case '/':return 2;

 case '^':

 case '$':return 3;

 }

 return 0;

}

void convert(char str[20])

{

 int i,j=0;

 char post[20],ch,ch1;

 init();

 for(i=0;str[i]!='\0';i++)

 { ch=str[i];

 switch(ch)

 {

 case '(':push(ch);

 break;

 case '+':

 case '-':

 case '*':

 case '/':

 case '$':

 case '^':

 while(!isempty() && (priority(peek())>=priority(ch)))

 {

 post[j]= pop();

 j++;

 }

 push(ch);

 break;

 case ')':while((ch1=pop())!='(')

 { post[j]=ch1;

 j++;

 }

 break;

 default:post[j]=ch;

 j++;


 }

 }

 while(!isempty())

 { post[j]=pop();

 j++;

}

post[j]='\0';

 printf("\n Postfix string = %s ",post);

}

main()

{

 char infix[20];

 printf("\nEnter the infix expression ");

 scanf("%s",infix);

 convert(infix);

}




Comments

Post a Comment

Popular posts from this blog

Slip 22_2: Read the data from file 'cities.txt' containing names of cities and their STD codes. Accept a name of the city from user and use sentinel linear search algorithm to check whether the name is present in the file and output the STD code, otherwise output “city not in the list”. Solution :

-
 Solution : #include<stdio.h> #include<stdlib.h> #include<string.h> struct city {  char name[20];  int code; }ct[10]; int readFile(struct city a[]) {  int i=0;  FILE *fp;  if((fp=fopen("city.txt","r"))!=NULL)  {  while(!feof(fp))  {  fscanf(fp,"%s%d",&a[i].name,&a[i].code);  i++;  }  }  return i-1; } void sentinelsearch(struct city a[10],int n,int sr) { int i,cnt=0;  a[n]=sr;  while(strcmp(sr,a[i].name)!=0) { i++;  }  if(i<n)  printf("city is found and STD code is %d ",a[i].code);  else  printf("city is not found "); } main() { int n;  char sr[20];  n=readFile(ct);  if(n==-1)  printf("File not found ");  else  {  printf("Enter city name to search");  scanf("%s",sr);  SentinelSearch(ct,n,sr);  } }
Read more

Slip10_2, 30_1 : Read the data from the file “employee.txt” and sort on names in alphabetical order (use strcmp) using bubble sort or selection sort

-
 Solution :Using Bubble sort #include<stdio.h> #include<stdlib.h> #include<string.h> struct employee {  char name[20];  int age; }emp[10]; int readfile(struct employee a[10]) {  int i=0;  FILE*fp;  if((fp=fopen("empl.txt","r"))!=NULL)  {  while(!feof(fp))  {  fscanf(fp,"%s%d",a[i].name ,&a[i].age);  i++;  }  }  return i-1; } void writefile(struct employee a[],int n) {  int i;  FILE *fp;  if((fp=fopen("bsort.txt","w"))!=NULL)  {  for(i=0;i<n;i++)  {  fprintf(fp,"%s %d \n",a[i].name ,a[i].age);  }  } } void bubblesort(struct employee a[],int n) {  int i,j;  struct employee temp;  for(i=0;i<n-1;i++)  {  for(j=0;j<n-1;j++)  {  if(strcmp(a[j].name,a[j+1].name)>0)  {  temp=a[j];  a[j]=a[j+1];  a[j+1]=temp;  }  }  } } main() { ...
Read more

Slip 23_2: Read the data from file ‘sortedcities.txt’ containing sorted names of cities and their STD codes. Accept a name of the city from user and use binary search algorithm to check whether the name is present in the file and output the STD code, otherwise output “city not in the list”.

-
 Solution : #include<stdio.h> #include<stdlib.h> #include<string.h> struct city {  char name[20];  int code; }ct[10]; int readFile(struct city a[]) {  int i=0;  FILE *fp;  if((fp=fopen("sortedfile.txt","r"))!=NULL)  {  while(!feof(fp))  {  fscanf(fp,"%s%d",&a[i].name,&a[i].code);  i++;  } }  return i-1; } int binarysearch(struct city a[10],int lb,int ub,char sr[20]) {  int mid=0;  while(lb<=ub)  {  mid=(lb+ub)/2;  if(strcmp(a[mid].name,sr)==0)  return mid;  else if(strcmp(sr,a[mid].name)<0)  ub=mid-1;  else  lb=mid+1;  }  return -1; } main() { int n,p;  char sr[20];  n=readFile(ct);  if(n==-1)  printf("File not found ");  else  {  printf("Enter city name to search ");  scanf("%s",sr);  p=binarysearch(ct,0,n,sr);  if(p>=0)  prin...
Read more