Difference between revisions of "Lecture23ECE264Spring2012" - Rhea

Revision as of 19:01, 7 May 2012

Lecture 23 _4/5_Kailu Song

Review for exam 2,students could ask question 1.read file FILE *fptr;

fptr = fopen(filename,"rb");

int a;

double b;

fread(&a,sizeof(int),1,fptr);

fread(&b,sizeof(double),1,fptr);

Person P;

fread(&P,sizeof(Person),1,fptr);

int arr[10];

fread(arr,sizeof(int),10,fptr);

int ch;

ch = fgetc(fptr);

char = oneline[256];

fets(oneline,256,fptr);

(stop at '\n', or reach the limit'\o');

int a,b;

fscanf(fptr,"%d %d", &a,&b);

strlen not include '\o';

strcpy,strstr,strcat;

2.linklist with n nodes sorted,insert one more value

3, three outcomes:1.file;2.structure;3.dynamic structure(linked list);

========================================

Shiyu Wang Lec23 April 8th

Review for Exam2

randon access

arr[5]

arr[29]

FILE* fptr; fptr = fopen(filename,"rb");

                   (binary)

int a;

double b;

fread(&a,sizeof(int),1 fptr);

fread(&b,sizeof(double),1,fptr);

int ch;

ch=fgetc(fptr);

char oneline[256];

fgets(oneline,256,fptr);

(it will stop at'\n' or reach the limit'\0')

How to use strcpy, strstr, strcat

=======

Kevin Tan(0023987592), section#2 notes 04/05

random access

arr[5]; arr[9];

FILE *fp= NULL; fp = fopen(filename,"rb");

int a; double b; fread(&a,sizeof(int),1,fp); fread(&b,sizeof(double),1,fp); . . fscanf(fp,"%d%d",&a,&b);

Wudi Zhou, Professor Lu's section, April 9th

Exam 2 covers: File I/O, Structure, Dynamic Structure,recursive

FILE * fptr; fptr = fopen(filename,"rb"); int a; double b; fread(&a, sizeof(int),1,fptr); fread(&b,sizeof(double),1,fptr);

fptr = fopen(filename,"b"); ch = fgetc(fptr); char oneline[256]; gets(oneline,256,fptr);

fscanf(fptr,"%d", &a);/*return 1 if successful*/ fscanf(fptr,"%d",&a, &b); /*return 2 if both successful*/

Person P; fread(&p, sizeof(person),1,fptr); int arr[10]; fread(arr,sizeof(int),10,fptr); fwrite(&p,sizeof(person),1,fptr);

Hanye Xu April 10

Exam 2 covers file input and file output fread and fsanf are not the same

fptr = fopen(filename,"rb");

int a;

double b;

fread(&a,sizeof(int),1,fptr);

fread(&b,sizeof(double),1,fptr);

Person P;

fread(&P,sizeof(Person),1,fptr);

int arr[10];

fread(arr,sizeof(int),10,fptr);

int ch;

ch = fgetc(fptr);

char = oneline[256];

fets(oneline,256,fptr);

(stop at '\n', or reach the limit'\o');

int a,b;

fscanf(fptr,"%d %d", &a,&b);

strlen not include '\o';

strcpy,strstr,strcat;

Lecture 0406 Huayi Guo taught by Niklas Nlmqvist /*

lecture0406

Anouncement:
Final exam
Sat , May 5 8am-10am
the location may not hold. And the exam will most likely be electronics.

• /

void Putcell(int x, int y, char c, int dim, char* block) {

 block[(y*dim)+x] =c;

}

int visitCell(int x,int y, int dim, char* block) {

  //drop the breadcrumb!
  putCell(x, y, "*", dim, data);
  
  //check neighbors;
  int count = 1;
  if(getcell(x-1, y, dim, data) =="1"){
    count += visitCell(x -1; y, dim, data):
  }
   if(getcell(x+1, y, dim, data) =="1"){
    count += visitCell(x +1; y, dim, data):
  }
  
  if(getcell(x, y-1, dim, data) =="1"){
    count += visitCell(x ; y-1, dim, data):
  }
   if(getcell(x, y+1, dim, data) =="1"){
    count += visitCell(x ; y+1, dim, data):
  }
  

}

int isconnected(int dim, char *block) {

 char *data = strdup(block);
 int x =0;
 int y=0;
 while(getCell(x, y dim, block) != '1'){
    x++;

if(x>= dim){ y++; x=0; }

  }  
  //REcursively visit each cell
  int numConnected = visitCell(x, y, dim, data);
  free(data);
  return numConnected = dim;

}

int getcell(int x, int y, int dim, char *block) {

  if(x<0 || x>=dim ||y<0 ||y>dim) return 0;
  return block[()]

}

int countones(int dim, char * block) {

  int i;
  int counter = 0;
  for(i =0; i < dim* dim; i++)
  {
    if( block[i] == '1'){

counter ++; }

  }
  return counter;

}

int main() {

 //check the command 
 if(argc != 2) 
 {
 
 }
 
 //open the file
 
 
 //initalization
 const int BUFFE_LENGTH =101;
 char buffer[];
 
 int valid = 0;
 int invalid = 0;
 
 while (fgets(buffer, BUFFER_LENGTH, buffer) != NULL){
    //consume any terminating newline

if(buffer[strelen(buffer)-1] =='\n') { buffer[strlen(buffer) -1] ='\0'; }

//Figure out the dimeconsion of the block int dim = sqrt(strlen(buffer));

// Rule 1: check that the dimension is valid if(dim * dim != strlen(buffer)){//if not n^2 then this one is invalid

       invalid++;

continue; // stops the loop and goes to next iteration //break, while stop the entire loop

    }

//Rule2 L check number of ones if(countones(dim, buffer) != dim) { invalid ++; continue; }

    //Rule3 : important! and hard!
    if(!isConnected(dim, buffer)){

invalid ++; continue ;

}

    //Rule4: for a zero, there should be no more than 1 neighbor that is 1??

}

//DFS //Depth-first search //BFS //breadth first search

===================

Rohan Khante

====================

exam review IMP- FREAD AND FSCANF are NOT the SAME

fptr = fopen(filename,"rb");

int a;

double b;

fread(&a,sizeof(int),1,fptr);

fread(&b,sizeof(double),1,fptr);

Person P;

fread(&P,sizeof(Person),1,fptr);

int arr[10];

fread(arr,sizeof(int),10,fptr);

int ch;

ch = fgetc(fptr);

char = oneline[256];

fets(oneline,256,fptr);

(stop at '\n', or reach the limit'\o');

int a,b;

fscanf(fptr,"%d %d", &a,&b);

strcpy,strstr,strcat; Strlen strstr and strcat were discussed NOTE- strlen DOES NOT include the termination character '\0'. so strlen performed on string have abc will return THREE

strstr- return a pointer to the first occurence of str2 in str1 or a null pointer if not found

strcat = concatenation function for strings. strcat("ece","264") will return ece264 string

NOTE2= all these functions are in string.h and this should be included in the header.

1. include <string.h>