C Programs and Algorithms

excellent NON-RECURSIVE algo for QUICK SORT

2011-01-03T06:16:00.000-08:00

/*------This algo is NON-RECURSIVE algo for QUICK SORT (as required in UPTU exams)------

The variables used are described as follows:
item- item part of node
next- next pointer address part of the node
a- pointer to the node to be sorted
FP- Node pointer to hold forward position of nodes
BP- Node pointer to hold backward position of nodes

Integer variables:
i- used in 'for' loops
Temp- temporary variable
Up- Used to hold INTEGER location of backward pointer
Down- Used to hold INTEGER location of Forward pointer
iUp- To save Up value for future use
iDown- To save Down value for future use
C- acts as counter
*/

QuickSort[a,FP,BP,t]
{
1. initialize i,Temp,loc,Up,Down,iUp,iDown,C,count;

2. set STACK[TOP]=NULL;

3. if(count==0)
PUSH(LAST);
PUSH(1);// 0 will be on top

4. Repeat while(STACK[TOP]!=NULL)
(a).set Down=STACK[TOP],loc=Down,iDown=Down, and POP();

(b).set Up=STACK[TOP],iUp=Up,and POP();

(c). set a=START and Repeat for i=1,2,3,...,loc
        a=a->next, and i=i+1

(d). set FP=START and Repeat for i=1,2,3,...,Down
        FP=FP->next, and i=i+1

(e). set BP=START and Repeat for i=1,2,3,...,Up
        BP=BP->next, and i=i+1

(f). Repeat until up>down
    (i).Reapeat for C=iDown,...,iUp, AND FP->item <= a->item
         FP=FP->next, and Down=Down+1;
      (ii).Repeat for C=iUp,....iDown AND BP->item > a->item
         set Up=Up-1, and BP=START;
   Repeat for i=1,2,..,Up.
         BP=BP->next;
   (iii).If(Up&gt>Down)
         Temp=BP->item;
         BP->item=FP->item;
       FP->item=Temp;

(g).Set Temp=a->item;
            a->item=BP->item;
            BP->item=Temp;

(h).if(Up-loc >= 2 && Up-1>=1)
       PUSH(Up-1);//up
       PUSH(loc);//down   //Partition1 of list
(i).if(iUp-Up >= 2)
      PUSH(iUp);//Up
      PUSH(Up+1);//down //Partition 2
5.exit.

//
Step 'a' and 'b' assigns the value on STACK[top] to 'up' and 'down' pointers.
Step 'c' takes the pointer 'a' to the location, of the pointer in the complete list, which needs to be sorted
Step 'd' takes the Forward pointer upto the 'down' location
Step 'e' takes the Backward pointer upto the 'up' location
Step 'f' performs quick sort mechanism on the partition and moves the pointers forward and backward
as required.
Step 'g' swaps the value at location 'up' with the value at location 'a', that is, the value which was to be sorted
Step 'h' and 'i' makes partition if there are more than 1 element to be sorted in the list.
//

Button for graphics program

2010-07-11T02:32:00.000-07:00

Addition using recursion

2010-07-11T02:30:00.000-07:00

#include
#include
int add(int);
void main()
{
int num,sum=0;
clrscr();
printf("How many no.s do u wanna add:");
scanf("%d",&num);
printf("\nEnter the no.s here:");
sum=add(num);
printf("The sum of the no.s is %d",sum);
getch();
}

int add(int x)
{
int n;
scanf("%d",&n);
if(x==0)
return(0);
else if(x==1)
return(n);
else
return(n+add(x-1));
}

cofactor value of matrix

2010-07-11T02:29:00.001-07:00

#include
#include
#include
int calculate(int);
int cofactor();
void main()
{
unsigned int m[25][25],t[24][25][25],c[25][25];
int i,j,p,q,x,y,or;
unsigned int value;
printf("Enter the order of the matrix:");
scanf("%d",&or);
printf("Enter the elements of the matrix:");
for(i=0;i for(j=0;j {
printf("\nEnter element[%d][%d]:",i+1,j+1);
scanf("%d",&m[i][j]);
}

if(or==0)
value=0;
else if(or==1)
value=m[0][0];
else if(or==2)
value+=calculate(0);
else
value+=cofactor();
printf("\nCofactor of the determinant is:");
for(i=0;i {
printf("\n|");
for(j=0;j printf("%d ",m[i][j]);
printf("|");
}
}

calculate(int docalctn)
{
if(docalctn==0)
return 0;
}

cofactor()
{
return 0;
}Cofa

Determinant of a matrix

2010-07-11T02:27:00.000-07:00

#include
#include
#include
static int count=0;
int mat[25][25][25];
int det(int order,int mat);
int cofactor(int mat,int order,int i,int j);
void main()
{
int i,j,order,val=0;
clrscr();

printf("Enter the order of the Matrix(Square matrix only):");
scanf("%d",&order);
printf("\n");
for(i=0;i for(j=0;j {
printf("Enter element [%d][%d]:",i+1,j+1);
scanf("%d",&mat[0][i][j]);
}
if(order==0)
{
printf("Sorry, A matrix must have atleast one element.");
getch();
main();
}
else if(order==1)
val=mat[0][0][0];
else
val=det(order,count);
printf("\nDeterminant of the Matrix is: %d",val);
getch();
}

int det(int order,int term)
{
int i,j,val=0;

if(order==2)
val=mat[term][0][0]*mat[term][1][1]-(mat[term][0][1]*mat[term][1][0]);
else
for(i=0;i val+=pow(-1,i+j+2)*(mat[term][i][0]*cofactor(term,order,i,0));
return(val);
}

int cofactor(int term,int order,int i,int j)
{
int value=0;
int p,q,x,y;
int neworder;
neworder=order-1;
count++;

for(x=0,p=0;p {
if(p==i)
x++;
for(y=0,q=0;q {
if(q==j)
y++;
mat[count][p][q]=mat[loc][x][y];
}
}
value=det(neworder,count);
return(value);
}

Character counting program

2010-07-11T02:26:00.000-07:00

#include
#include
#include
void main()
{
FILE *fp;
int count_space=0,count_chars=0,count_tab=0,count_line=0;
char name[20],fname[20],str;
clrscr();
printf("\nEnter the name of text file to be created:\n");
gets(name);
strcpy(fname,name);
strcat(fname,".txt");

if((fp=fopen(fname,"w"))==NULL)
{
printf("\n\tSorry, file could not be created.");
printf("\n\tProgram will exit now.");
delay(2000);
exit(0);
}
else
{
printf("\nA file with name '%s' has been created.",fname);
printf("Now enter the string please.");
printf("\n(Press 'Esc' to quit entering string):\n");
do
{
if((str=getch())!='\r')
{
printf("%c",str);
if(str==' ')
str='-';
}
else
{
printf("\n");
str='|';
}
putc(str,fp);
}while(str!=27);
///Esc key
fclose(fp);
}
fp=fopen(fname,"r");
if(fp==NULL)
{
printf("\nSorry, File Read Error.The program will exit now.");
delay(2000);
exit(0);
}
else
{
while(!feof(fp))
{
str=getc(fp);
count_chars++;
if(str=='-')
count_space++;
else if(str=='\t')
count_tab++;
else if(str=='|')
count_line++;
}
count_chars-=count_space;
count_chars-=count_tab;
count_chars-=count_line;
count_chars-=2;
printf("\n\t-------------------------------");
printf("\n\tDetails");
printf("\n\t-------------------------------");
printf("\n\tFilename: %s",fname);
printf("\n\tNo. of Characters in file: %d characters (alphabets+other characters),",count_chars);
printf("\n\tNo. of Spaces in file: %d spaces,",count_space);
printf("\n\tNo. of Tabs in file: %d tabs,",count_tab);
printf("\n\tNo. of Newlines in file: %d newlines.",count_line);
}
getch();
}

Data copying program

2010-07-11T02:23:00.001-07:00

#include
#include
void main()
{
char oldfname[50],newfname[50],x,ch;
FILE *fp1,*fp2;
clrscr();

printf("------------Program to copy data from one file to another------------");
printf("\nEnter the source/name of source file:");
gets(oldfname);
fp1=fopen(oldfname,"r");
if(fp1==NULL)
{
printf("\nSorry, No such files exist.The program will exit now.");
getch();
exit(0);
}
else
{
printf("\nEnter the name of destination file:");
gets(newfname);
fp2=fopen(newfname,"w");
while(!feof(fp1))
{
x=getc(fp1);
putc(x,fp2);
}
printf("\nData from '%s' has been copied to '%s'.",oldfname,newfname);
printf("\nDo you want to see it?(y/n):");
ch=getch();
printf("%c\n",ch);
if(ch=='Y'||ch=='y')
{
rewind(fp2);
while(!feof(fp2))
printf("%c",getc(fp2));
}
else
printf("\nOk, the program will exit now.");
}
getch();
}

File creation program

2010-07-11T02:20:00.000-07:00

#include
#include
void main()
{
FILE *fp;
char ch,fname[20];
clrscr();

printf("Enter the name of the file to be created:");
gets(fname);
fp=fopen(fname,"w");
printf("Now hit any key to store it in file.");
printf("(Press 'Esc' to break):\n");
do
{
printf("%c",(ch=getch()));
if(ch==' ')
ch='-';
if(ch=='\r')
printf("\n");
putc(ch,fp);
}while(ch!=27);
fclose(fp);
printf("\nData has been saved into file.Do you want to see it?(y/n):");
printf("%c",(ch=getch()));
if(ch=='Y'||ch=='y')
{
printf("\n");
fp=fopen(fname,"r");
while(!feof(fp))
{
ch=getc(fp);
if(ch=='-')
ch=' ';
printf("%c",ch);
}
}
else
printf("\nOk Thanks! The program will exit now.");
getch();
}

Matrix Transpose (using array)

2010-07-11T02:18:00.000-07:00

#include
#include
void main()
{
int i,j,m,n,mat[9][9];
clrscr();
printf("Enter the order of matrix:\n");
scanf("%d%d",&m,&n);
printf("Enter the matrix terms:\n\n");
for(i=0;i{
for(j=0;j{
gotoxy(10+4*j,5+2*i);
scanf("%d",&mat[i][j]);
}}
printf("\nThe original matrix is:\n\n");
for(i=0;i{
printf("\t|");
{
for(j=0;jprintf("%3d",mat[i][j]);
}
printf("|\n");
}
printf("\nThe Transpose of the above matrix is:\n\n");
for(j=0;j{
printf("|");
for(i=0;i{
printf("%3d",mat[i][j]);
}
printf(" |\n");
}
getch();
}

Simple Structure program

2010-07-11T02:13:00.000-07:00

#include
#include

struct classdata{
char name[20],rollno[15];
int age,height;
};

void main()
{
int i=1,j;
char choice;
struct classdata db[30];
clrscr();

printf("\n-----Data Entry for Students -----");
do
{
printf("\n\n\t\tEnter the Student's name: ");
scanf("%s",db[i].name);
printf("\t\tEnter Roll Number: ");
scanf("%s",db[i].rollno);
printf("\t\tEnter age: ");
scanf("%d",&db[i].age);
printf("\t\tEnter height: ");
scanf("%d",&db[i].height);
printf("\n\tEntry for Mr. %s has been saved.",db[i].name);
printf("\nDo you want to enter data for someone else? (Press Y/y for Yes):");
scanf("%s",&choice);
i++;
}while(choice=='Y'||choice=='y');

printf("\n\n\t\t----------------------------------------------");
printf("\n\t\tName\t\tRoll No.\tAge\tHeight");
printf("\n\t\t----------------------------------------------\n");

for(j=1;j{
printf("\n\t\t%s",db[j].name);
printf("\t\t%s",db[j].rollno);
printf("\t%d Yrs",db[j].age);
printf("\t%d cms",db[j].height);
}
printf("\n\t\t----------------------------------------------");
getch();
}