Thread: cant see what certain part of this code does..

There is an election on 3 colleges.
For places on the board and for the place of the chairman.
There are 10 candidates ,each candidate represented by a number from 0 to 9.
Each student has the right (doesnt have to )to vote 3 times,two votes for members of the board,and one vote for chairman.
Three files with the votes are coming to the counting committee .
In each file each vote represented by a line:
name -30 chars
id -9 chars
type of vote("1" for chair man," 2" for board) -1 char
number of candidate -1 char.

Each file is sorted by id number in ascending order.
Write a function.
void report(FILE* college[3], FILE* arr[10], char* canceled);
College is the votes files,and it creates 10 new files FILE* arr[10] one file for each candidate.
Each candidate file concentrates the legal votes for this candidate.
for each vote in each row we have:
id -9 chars
number of college(0-2) -1 char
type of vote("1" for chair man," 2" for board) -1 char.

Each file is sorted by id number in ascending order.

Also the function need to create a file name which is stored in the canceled string for the illegal votes.
each line has:
name -30 chars
id -9 chars
type of cancellation : "1" if he voted twice for the same candidate.
"2" if he voted for chairman for more then one time,or if he voted for board for more then two times.
"3" if he voted from more then one college
file is sorted by id number in ascending order.

If a student is mentioned in the canceled file ,his votes cannot be shown in the 10 candidate files.

i understand this solution till this comment
//Filling struct table for the minimal id
i got the idea that index represents the file with minimal id

Code:

eof[index]=fscanf(college[index],"%30s%9d%1d%1d%*c",
current.name,&current.id,&current.type,&current.candidate);

currect represent the line of index so they are the same/

why current.id needs to differ idmin??(its always not)
why i=1 and not 0?? (files start from 0)

from this part i cant see what the code means??
what each subpart does in general
??

Code:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
 

 
typedef struct vote {
	char name [30];
	int id,type,candidate;
} vote;
void report(FILE* college[3], FILE* arr[10], char* canceled);
// Fuction returns the minimal id
int getMin(int eof[],vote [],int *);
// Function checks a vote record correct
int votecheck(vote ,vote [],int i);
// Function reads the next record from "college" file
int readFrom(FILE *,vote [],int);



int main ()
{
FILE* f[10];
FILE* c[3];
char*  name="c:\\canceled.txt";

c[0]=fopen("c:\\file1.txt","r");//vote files ,each file represents the votes from a college
c[1]=fopen("c:\\file2.txt","r");
c[2]=fopen("c:\\file3.txt","r");
f[0]=fopen("c:\\cfile1.txt","w");//condidate files
f[1]=fopen("c:\\cfile2.txt","w");
f[2]=fopen("c:\\cfile3.txt","w");
f[3]=fopen("c:\\cfile4.txt","w");
f[4]=fopen("c:\\cfile5.txt","w");
f[5]=fopen("c:\\cfile6.txt","w");
f[6]=fopen("c:\\cfile7.txt","w");
f[7]=fopen("c:\\cfile8.txt","w");
f[8]=fopen("c:\\cfile9.txt","w");
f[9]=fopen("c:\\cfile10.txt","w");

report(c, f, name);

fclose(c[0]);
fclose(c[1]);
fclose(c[2]);
fclose(f[0]);
fclose(f[1]);
fclose(f[2]);
fclose(f[3]);
fclose(f[4]);
fclose(f[5]);
fclose(f[6]);
fclose(f[7]);
fclose(f[8]);
fclose(f[9]);
 

	return 0;
}
void  report(FILE *college[3], FILE *arr[10], char* canceled){
	FILE *cancel;
	vote currtable[3], // array for three current "college" records
		votable[3],    // array for checking the records with the same "id"
		current;	   // struct for the current "college" record	
	int i,j,idmin,index,flag,eof[3];
	if(!(cancel=fopen(canceled,"w"))) exit(1);
	
	for(i=0;i<3;i++)
		eof[i]= readFrom(college[i],currtable,i);
// main loop	
	while(eof[0]!=EOF||eof[1]!=EOF||eof[2]!=EOF){
		idmin=getMin(eof,currtable,&index);
		for(i=flag=0;i<3;i++)
			if(i!=index && eof[i]!=EOF && currtable[i].id==idmin)
				flag=3;
		if(flag){
		fprintf(cancel,"%s%d%d\n",currtable[index].name,idmin,flag);
			for(i=0;i<3;i++)
				while(eof[i]!=EOF && currtable[i].id==idmin)
				eof[i]=readFrom(college[i],currtable,i);
			continue;
		}
//Filling struct table for the minimal id
		votable[0]=currtable[index];
		i=1;
		while(eof[index]!=EOF && i<3){
			eof[index]=fscanf(college[index],"%30s%9d%1d%1d%*c",
current.name,&current.id,&current.type,&current.candidate);
		if(current.id!=idmin){
			for(j=0;j<i;j++)
				fprintf(arr[votable[j].candidate],"%9d%d%d\n",
idmin,index,votable[j].type);
		currtable[index]=current;
		break;
		}
		else{
			flag=votecheck(current,votable,i);
			if(flag){				fprintf(cancel,"%s%d%d\n",currtable[index].name,idmin,flag);
			while(eof[index]!=EOF && currtable[index].id==idmin)
			eof[index]=readFrom(college[index],currtable,index);
			break;
			}
			else
				votable[i++]=current;
		}//else
	}//while
	if(i<3)  continue;
		if(eof[index]!=EOF)
		eof[index]=fscanf(college[index],"%30[^\n]%9d%1d%1d%*c",
current.name,&current.id,&current.type,&current.candidate);
		if(eof[index]==EOF ||current.id!=idmin ){
			for(j=0;j<i;j++)
				fprintf(arr[votable[j].candidate],"%9d%d%d\n",
idmin,index,votable[j].type);		
			currtable[index]=current;
		}
		else{			fprintf(cancel,"%s%d%d\n",votable[0].name,idmin,2);
	while(eof[index]!=EOF && currtable[index].id==idmin)
		eof[index]=readFrom(college[index],currtable,index);
		}
	}// main loop - while
	fclose(cancel);
}// report

int votecheck(vote curr,vote arr[],int i){
	int j,count;
	for(j=count=0;j<i;j++){
		if(curr.candidate==arr[j].candidate)
			return 1;
		if(curr.type==1 && arr[j].type==1)
			return 2;
		if(curr.type==2 && arr[j].type==2)
			count++;
		if(count>1)	return 2;
	}
	return 0;
}

int readFrom(FILE *coll,vote table[],int i){
	return fscanf(coll,"%30s%9d%1d%1d%*c",table[i].name,
				&table[i].id,&table[i].type,&table[i].candidate);
}	

int getMin(int eof[],vote table[],int *index){
	int i,idmin;
	for(i=0,idmin=999999999;i<3;i++)
		if(eof[i]!=EOF && table[i].id<idmin){
				idmin=table[i].id;
				*index=i;
		}
	return idmin;			
}

Although C gets us counting from zero on up, nobody else is likely to join in. They don't say "I've got zero dogs", to mean they have 1 dog. Same with these students, the first one will be numbered from one, instead of from zero.

Your assignments have certainly gotten longer and more involved!

currect represent the line of index so they are the same/

why current.id needs to differ idmin??(its always not)

i managed to intend this code
what is the role
of the red part
and blue part?

Code:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
 

 
typedef struct vote {
	char name [30];
	int id,type,candidate;
} vote;
void report(FILE* college[3], FILE* arr[10], char* canceled);
// Fuction returns the minimal id
int getMin(int eof[],vote [],int *);
// Function checks a vote record correct
int votecheck(vote ,vote [],int i);
// Function reads the next record from "college" file
int readFrom(FILE *,vote [],int);



int main ()
{
FILE* f[10];
FILE* c[3];
char*  name="c:\\canceled.txt";

c[0]=fopen("c:\\file1.txt","r");//vote files ,each file represents the votes from a college
c[1]=fopen("c:\\file2.txt","r");
c[2]=fopen("c:\\file3.txt","r");
f[0]=fopen("c:\\cfile1.txt","w");//condidate files
f[1]=fopen("c:\\cfile2.txt","w");
f[2]=fopen("c:\\cfile3.txt","w");
f[3]=fopen("c:\\cfile4.txt","w");
f[4]=fopen("c:\\cfile5.txt","w");
f[5]=fopen("c:\\cfile6.txt","w");
f[6]=fopen("c:\\cfile7.txt","w");
f[7]=fopen("c:\\cfile8.txt","w");
f[8]=fopen("c:\\cfile9.txt","w");
f[9]=fopen("c:\\cfile10.txt","w");

report(c, f, name);

fclose(c[0]);
fclose(c[1]);
fclose(c[2]);
fclose(f[0]);
fclose(f[1]);
fclose(f[2]);
fclose(f[3]);
fclose(f[4]);
fclose(f[5]);
fclose(f[6]);
fclose(f[7]);
fclose(f[8]);
fclose(f[9]);
 

	return 0;
}
void  report(FILE *college[3], FILE *arr[10], char* canceled){
	FILE *cancel;
	vote currtable[3], // array for three current "college" records
		votable[3],    // array for checking the records with the same "id"
		current;	   // struct for the current "college" record	
	int i,j,idmin,index,flag,eof[3];
	if(!(cancel=fopen(canceled,"w"))) exit(1);
	
	for(i=0;i<3;i++)
		eof[i]= readFrom(college[i],currtable,i);
// main loop	
	while(eof[0]!=EOF||eof[1]!=EOF||eof[2]!=EOF)
	{
		idmin=getMin(eof,currtable,&index);
		for(i=flag=0;i<3;i++)
			if(i!=index && eof[i]!=EOF && currtable[i].id==idmin)
				flag=3;
		if(flag)
		{
		    fprintf(cancel,"%s%d%d\n",currtable[index].name,idmin,flag);
			for(i=0;i<3;i++)
				while(eof[i]!=EOF && currtable[i].id==idmin)
				eof[i]=readFrom(college[i],currtable,i);
			continue;
		}
         //Filling struct table for the minimal id
		votable[0]=currtable[index];
		i=1;
		while(eof[index]!=EOF && i<3)
		{
			eof[index]=fscanf(college[index],"%30s%9d%1d%1d%*c",current.name,&current.id,&current.type,&current.candidate);
		    if(current.id!=idmin)
			{
			    for(j=0;j<i;j++)
				fprintf(arr[votable[j].candidate],"%9d%d%d\n",idmin,index,votable[j].type);
		        currtable[index]=current;
		        break;
		     }
		     else
			 {
			        flag=votecheck(current,votable,i);
			        if(flag)
			        {
  				        fprintf(cancel,"%s%d%d\n",currtable[index].name,idmin,flag);
			            while(eof[index]!=EOF && currtable[index].id==idmin)
			            eof[index]=readFrom(college[index],currtable,index);
			            break;
			         }
			         else
				     votable[i++]=current;
		      }//else
	      }//while
	      if(i<3)  continue;
		  if(eof[index]!=EOF)
		  eof[index]=fscanf(college[index],"%30[^\n]%9d%1d%1d%*c",current.name,&current.id,&current.type,&current.candidate);
		  if(eof[index]==EOF ||current.id!=idmin )
		  {
			  for(j=0;j<i;j++)
			  fprintf(arr[votable[j].candidate],"%9d%d%d\n",idmin,index,votable[j].type);		
			  currtable[index]=current;
 		  }
		  else
		  {
		      fprintf(cancel,"%s%d%d\n",votable[0].name,idmin,2);
              while(eof[index]!=EOF && currtable[index].id==idmin)
		      eof[index]=readFrom(college[index],currtable,index);
		  }
	}// main loop - while
	fclose(cancel);
}// report

int votecheck(vote curr,vote arr[],int i)
 {
	int j,count;
	for(j=count=0;j<i;j++){
		if(curr.candidate==arr[j].candidate)
			return 1;
		if(curr.type==1 && arr[j].type==1)
			return 2;
		if(curr.type==2 && arr[j].type==2)
			count++;
		if(count>1)	return 2;
	}
	return 0;
}

int readFrom(FILE *coll,vote table[],int i)
{
	return fscanf(coll,"%30s%9d%1d%1d%*c",table[i].name,
				&table[i].id,&table[i].type,&table[i].candidate);
}	

int getMin(int eof[],vote table[],int *index)
{
	int i,idmin;
	for(i=0,idmin=999999999;i<3;i++)
		if(eof[i]!=EOF && table[i].id<idmin)
		{
				idmin=table[i].id;
				*index=i;
		}
	return idmin;			
}

what this part does

Code:

//Filling struct table for the minimal id
		votable[0]=currtable[index];
		i=1;
		while(eof[index]!=EOF && i<3)
		{
			eof[index]=fscanf(college[index],"%30s%9d%1d%1d%*c",current.name,&current.id,&current.type,&current.candidate);
		    if(current.id!=idmin)
			{
			    for(j=0;j<i;j++)
				fprintf(arr[votable[j].candidate],"%9d%d%d\n",idmin,index,votable[j].type);
		        currtable[index]=current;
		        break;
		     }
		     else
			 {
			        flag=votecheck(current,votable,i);
			        if(flag)
			        {
  				        fprintf(cancel,"%s%d%d\n",currtable[index].name,idmin,flag);
			            while(eof[index]!=EOF && currtable[index].id==idmin)
			            eof[index]=readFrom(college[index],currtable,index);
			            break;
			         }
			         else
				     votable[i++]=current;
		      }//else
	      }//while
	      if(i<3)  continue;
		  if(eof[index]!=EOF)
		  eof[index]=fscanf(college[index],"%30[^\n]%9d%1d%1d%*c",current.name,&current.id,&current.type,&current.candidate);
		  if(eof[index]==EOF ||current.id!=idmin )
		  {
			  for(j=0;j<i;j++)
			  fprintf(arr[votable[j].candidate],"%9d%d%d\n",idmin,index,votable[j].type);		
			  currtable[index]=current;
 		  }
		  else
		  {
		      fprintf(cancel,"%s%d%d\n",votable[0].name,idmin,2);
              while(eof[index]!=EOF && currtable[index].id==idmin)
		      eof[index]=readFrom(college[index],currtable,index);
		  }
	}// main loop - while
	fclose(cancel);
}// report