/* Subject: Contest submission for problem #1, file 1.c */
/* cs169-ta@imail.EECS.Berkeley.EDU */
/* Fri Sep 19 01:42:52 PDT 2003 */
/*___CONTEST_SUBMISSION___ cs169-ta 1 */
/*
John Han
9/12/03
Est Time:     3 hours
Actual Time: ~3:30 hours
*/

//#include <stdio.h>
//#include <string.h>
#include "contest.h"

struct statement{
  char defvars[50];
  int defvarsiter;

  //all of the line referencing this line
  int gotolines[50];
  int gotoiter;
};

struct statement newStat(char defvars[], int defvarsiter, int gotolines[], int gotolinesiter){
  int i=0;
  struct statement temp;

  for(i=0; i<defvarsiter; i++){
    temp.defvars[i]=defvars[i];
  }
  for(i=0; i<gotolinesiter; i++){
    temp.gotolines[i]=gotolines[i];
  } 
  return temp;
}

void setStat(struct statement temp[], int label, char defvar){

  temp[label].defvars[temp[label].defvarsiter]=defvar;
  temp[label].defvarsiter++;
  //printf("setting %c a position %i\n", temp[label].defvars[temp[label].defvarsiter-1], temp[label].defvarsiter);
}


int contains(char test, char array[], int size){
  int i;
  for (i=0; i<size; i++)
    if (test == array[i])      //      printf("contains %c\n", test);
      return 1;
  return -1;
}


void setGoto(struct statement temp[], int targetlabel, int sourcelabel){
  temp[targetlabel].gotolines[temp[targetlabel].gotoiter] = sourcelabel;
  temp[targetlabel].gotoiter++;
  //  printf("goto setting %i a position %i\n", temp[targetlabel].gotolines[temp[targetlabel].gotoiter-1], temp[targetlabel].gotoiter);
}



int main(){
  struct statement statements[50];
  
  //store the data members for statement structs
  char defvars[50];
  int gotolines[50];
  int label;
  
  //some variables to take care of parsing
  int c=1;
  char refchar;
  char statement[50];
  int statiter=0;
  char defval;
  char ref[50];

  int program=0;
  int scan=0;
  int i=0;
  int j=0;
  int x=0;

  int gt=0;
  char brk = 'n';

  //initialize values
  for (x=0; x<50; x++){
    defvars[i]='\0';
    gotolines[i]=-1;
  }
  for (x=0; x<50; x++)
    statements[x] = newStat(defvars, 0, gotolines, 0);

  while((c=getchar())!=EOF){
    ungetc(c, stdout);
  //  for (x=0; x<3; x++){
    //loop through each program
    while(strcmp(statement, "stop") != 0){
      for (j=0; j<50; j++)
	statement[j]='\0';
    statiter=0;

    //get rid of free form characters and parse line by line
    while((c=getchar()) != ';'){
      if((c!= ' ') && (c != '\n') && (c != '\r') && (c != '\f') && (c != '\t') && (c != '\v')){
	statement[statiter]=c;
        statiter++;
      }
    }

    sscanf(statement, "%i: %s", &label, statement);
    //    printf("program %i label %i %s\n", program, label, statement);        

    //first set the variables defined at a given line equal to defvars of the preceding line
    for(i=0; i<statements[label-1].defvarsiter; i++){
      statements[label].defvars[i]=statements[label-1].defvars[i];
      statements[label].defvarsiter++;
    }
    
    //if you find an assignment instruction
    if (sscanf(statement,"%c = F(%s", &defval, ref) == 2){
      //if you don't already have an entry for the variable set, then record that variable as set
      if (contains(defval, statements[label].defvars, statements[label].defvarsiter)==-1)
	setStat(statements, label, defval);

      //scan for any variables referenced
      while(1){
	scan = sscanf(ref, "%c, %s", &refchar, ref);
	//printf("refchar %c ref %s\n", refchar, ref);

	if(refchar!=')'){
	  //check that any variable references has already been defined
	  if (contains(refchar, statements[label].defvars, statements[label].defvarsiter) == -1){
	    printf("Set %i: Possible use before definition\n", program);
	    brk='y';
	    break;
	  }	  
	  //for each line linking to this line
	  for(i=0; i<statements[label].gotoiter; i++){
	    //make sure that the line originating the link defines all vars referenced
	    if (contains(refchar, statements[statements[label].gotolines[i]].defvars, statements[statements[label].gotolines[i]].defvarsiter) == -1){
	      printf("Set %i: Possible use before definition\n", program);
	      brk='y';	      break;
	    }      
	  }
	}  
	  if(scan==1)
	    break;      
      }
    }
    //you've reached an if statement
    else {
      sscanf(statement, "if F( %s", ref);
      //      printf("ref %s %i\n", ref, gt);
  
      while(1){
	scan = sscanf(ref, "%c, %s", &refchar, ref);
	//printf("refchar %c\n", refchar);
	//printf("scan %i\n", scan);

	if (refchar != ')' && contains(refchar, statements[label].defvars, statements[label].defvarsiter)==-1){
	  printf("Set %i: Possible use before definition\n", program);
	  brk='y';
	  break;
	  }
     
	if(scan==1)
	    break;
      }
      sscanf(ref, "%c )goto %s", &refchar, ref);
      sscanf(ref, "%i", &gt);
      setGoto(statements, gt, label);
      //      printf("gt %i\n", gt);
    }
    if(brk == 'y')
      break;
    }
    if(brk == 'n')
      printf("Set %i: No use before definition\n", program);
    brk='n';

    //if you broke from the loop early, dump everything until stop 
    while(strcmp(statement, "stop") != 0){
      //printf("%s****\n", statement);
      for (j=0; j<50; j++)
	statement[j]='\0';
      statiter=0;
      while((c=getchar()) != ';' && c != EOF){
	if((c!= ' ') && (c != '\n') && (c != '\r') && (c != '\f') && (c != '\t') && (c != '\v')){
	  statement[statiter]=c;
	  //printf("%s\n", statement);
	  statiter++;
	}
      }
      sscanf(statement, "%i: %s", &label, statement);
    }
    gets(statement); 
    program ++;
  }
  printf("\n");
  return 1;
  exit(0);
}