c - Infix notation to postfix notation using stack -


i trying convert infix notation postfix notation using stack. have written following code giving me error:

/users/apple/desktop/infix.c|49|error: expected expression

and unable find error. please me correct code.

 #include <stdio.h>  #include <string.h>  #include <stdlib.h>  #include <ctype.h>   #define max 100   char st[max];  int top = -1;   void push(char st[],char);  char pop(char st[]);  void infixtopostfix(char source[],char target[]);  int getpriority(char);   int main(){     char infix[100],postfix[100];     printf("enter infix expression");     fflush(stdin);     gets(infix);     strcpy(postfix,"");     infixtopostfix(infix,postfix);     printf("\nthe corresponding postfix expression is:");     puts(postfix);     return 0; } void infixtopostfix(char source[],char target[]){     int i=0,j=0;     char temp;     strcpy(target,"");     while(source[i]!='\0')     {         if(source[i]=='(')         {             push(st,source[i]);             i++;         }         else if(source[i]==')')         {             while((top!=-1)&&(st[top]!='('))             {                 target[j]=pop(st);                 j++;             }             if(top==-1)             {                 printf("\nincorrect syntax");                 exit(1);             }             temp=pop(st);             i++;             else if((isdigit(source[i]))||(isalpha(source[i]))             {                 target[j]=source[i];                 j++;                 i++;             }             else if(source[i]=='+'||source[i]=='-  '||source[i]=='*'||source[i]='/'||source[i]=='%d')             {                 while((top!=-1)&&(st[top]!='(')&&(getpriority(st[top])>getpriority(source[i])))                 {                     target[j]=target[i];                     i++;                 }                 push(st,source[i]);                 i++;             }             else{                 printf("\nincorrect expression");                 exit(1);             }         }         while((top!=-1)&&(st[top]!='('))         {             target[j]=pop(st);             j++;         }         target[j]='\0';      } } int getpriority(char op) {     if(op=='/'||op=='*'||op=='%'||op=='%')     return 1;     else if(op=='+'||op=='-')     return 0; } void push(char st[],char val) {     if(top==max-1)         printf("overflow");     else{         top++;         st[top]=val;     } } char pop(char st[]) {     char val=' ';     if(top==-1)         printf("underflow");     else{         val=st[top];         top--;     }     return val; }

many problems, important 1 being

else if((isdigit(source[i]))||(isalpha(source[i]))

lacks closing parentheses, coding style makes difficult notice

else if ((isdigit(source[i]) != 0) || (isalpha(source[i]) != 0))

and don't use gets() it's deprecated, in case

fgets(infix, sizeof(infix), stdin);

would work, , have benefit of preventing buffer overflow.


-

Comments

Post a Comment

Popular posts from this blog

OpenCV OpenCL: Convert Mat to Bitmap in JNI Layer for Android -

there several posts converting mat bitmap using utils.mattobitmap() function. i'm assuming function can called in java layer after importing utils class. i want transfer data memory address pointed uint32_t* bmpcontent; in code below. jniexport void jnicall java_com_nod_nodcv_nodcvactivity_runfilter( jnienv *env, jclass clazz, jobject outbmp, jbytearray indata, jint width, jint height, jint choice, jint filter) { int outsz = width*height; int insz = outsz + outsz/2; androidbitmapinfo bmpinfo; if (androidbitmap_getinfo(env, outbmp, &bmpinfo) < 0) { throwjavaexception(env,"gaussianblur","error retrieving bitmap meta data"); return; } if (bmpinfo.format != android_bitmap_format_rgba_8888) { throwjavaexception(env,"gaussianblur","expecting rgba_8888 format"); return; } uint32_t* bmpcontent; if (androidbitmap_lockpixels(env, outbmp,(void**)&bmpcontent)...
Read more

android - org.xmlpull.v1.XmlPullParserException: expected: START_TAG {http://schemas.xmlsoap.org/soap/envelope/}Envelope -

i trying hit soap api in application login purpose , getting above mentioned error , can 1 tell me going wrong , first time soap apis. here code hit soap :- vector<object> args = new vector<object>(); hashtable<string, object> hashtable = new hashtable<string, object>(); hashtable.put("email", "mss.siddhart28@gmail.com"); hashtable.put("password", "siddharth"); args.add(hashtable); soapserializationenvelope envelope = new soapserializationenvelope( soapenvelope.ver11); envelope.dotnet = true; envelope.xsd = soapserializationenvelope.xsd; envelope.enc = soapserializationenvelope.enc; (new marshalhashtable()).register(envelope); httptransportse androidhttptransport = new httptransportse( "http://tempuri.org/", 15000); androidhttptransport.debug = true; string result = ""; try { soapobject request = new soapobject("http:...
Read more

python - How to remove the Xframe Options header in django? -

i have made page has iframe . inside iframe want show multiple different links article facebook, or news, or youtube video or other possible url. but, due xframe header, unable so. referred following link: https://docs.djangoproject.com/en/1.8/ref/clickjacking/ , django xframeoptionsmiddleware (x-frame-options) - allow iframe client ip but didn't help. my settings.py file's middleware_classes is: middleware_classes = ( 'django.contrib.sessions.middleware.sessionmiddleware', 'django.middleware.common.commonmiddleware', 'django.middleware.csrf.csrfviewmiddleware', 'django.contrib.auth.middleware.authenticationmiddleware', 'django.contrib.auth.middleware.sessionauthenticationmiddleware', 'django.contrib.messages.middleware.messagemiddleware', 'django.middleware.clickjacking.xframeoptionsmiddleware', ) from http://django-secure.readthedocs.org/en/latest/middleware.html , found using ...
Read more