Matrix Transpose

/* Transpose the matrix */
#include<stdio.h>

int main()
{
int a[4][4],i,j,b;

for(i=0;i<4;i++)
{
printf("\nEnter elements of %d row of Matrix: ",i+1);
for(j=0;j<4;j++)
scanf("%d",&a[i][j]);
}

for(i=0;i<4;i++)
{
for(j=i+1;j<4;j++)
{
b=a[i][j];
a[i][j]=a[j][i];
a[j][i]=b;
}
}

printf("\nTransposed Matrix:\n\n");
for(i=0;i<4;i++)
{
for(j=0;j<4;j++)
printf("%4d",a[i][j]);
printf("\n");
}
return 0;
}

Sum of two Matrix

/* Sum of two Matrix */
#include<stdio.h>

int main()
{
int a[5][5],b[5][5],c[5][5];
int i,j;

for(i=0;i<5;i++)
{
printf("\nEnter elements of %d row of first Matrix: ",i+1);
for(j=0;j<5;j++)
scanf("%d",&a[i][j]);
}

for(i=0;i<5;i++)
{
printf("\nEnter elements of %d row of 2nd Matrix: ",i+1);
for(j=0;j<5;j++)
scanf("%d",&b[i][j]);
}

printf("\nSum of Matrix:\n\n");
for(i=0;i<5;i++)
{
for(j=0;j<5;j++)
{
c[i][j]=a[i][j]+b[i][j];
printf("%3d ",c[i][j]);
}
printf("\n");
}
return 0;
}

Matrix Multiplication

/* Matrix multiplication */
#include<stdio.h>

int main()
{
int arr1[3][3],arr2[3][3],arr3[3][3]={0},i,j,k;

printf("Type a matrix of 3 rows & 3 colomns :\n");
for(i=0;i<3;i++)
for(j=0;j<3;j++)
scanf("%d",&arr1[i][j]);

printf("Type another matrix of 3 rows & 3 colomns :\n");
for(i=0;i<3;i++)
for(j=0;j<3;j++)
scanf("%d",&arr2[i][j]);

for(i=0;i<3;i++)
{
for(j=0;j<3;j++)
{
for(k=0;k<3;k++)
arr3[i][j]=arr3[i][j]+arr1[i][k]*arr2[k][j];
}

}

printf("\n\nOutput:\n");
for(i=0;i<3;i++)
{
for(j=0;j<3;j++)
printf("%5d",arr3[i][j]);
printf("\n\n");
}

return 0;
}

Sort array of 10 strings

/* Sort array of 10 strings. */

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

int main()
{
 int i,j;
 char str[10][10],temp[10];
 printf("Type 10 names :\n");
 for(i=0;i<10;i++)
 {
  // gets(str[i]);
  // fgets is a better option over gets to read multiword string .
  fgets(str[i], 10, stdin);
 }
 for(i=0;i<10;i++)
 {
  for(j=0;j<10-1-i;j++)
  {
   if(strcmpi(str[j],str[j+1])>0)
   {
    strcpy(temp,str[j]);
    strcpy(str[j],str[j+1]);
    strcpy(str[j+1],temp);
   }
  }
 }
   
 printf("\nSorted Names :\n");
 for(i=0;i<10;i++)
  puts(str[i]);
 return 0;
}

Insertion Sort

/* Insertion Sort */

#include<stdio.h>

int main()
{
 int arr[10],i,j,new;
 printf("Please enter 10 values:\n");
 for(i=0;i<10;i++)
  scanf("%d",&arr[i]);
 
 for(i=1;i<10;i++)
 {
  new=a[i];
  for(j=i-1;j>=0&&new<a[j];j--)
  {
   a[j+1]=a[j];
  }
  a[j+1]=new;
 }
  
 printf("Sorted Array is:\n");
 for(i=0;i<10;i++)
  printf("%d\n",arr[i]);
 
 return 0;
}

Selection Sort

/* Selection Sort */

#include<stdio.h>

int main()
{
 int arr[10],i,j,k,t;
 printf("Please enter 10 values:\n");
 for(i=0;i<10;i++)
  scanf("%d",&arr[i]);
 
 for(i=0;i<10;i++)
 {
  k=i;
  for(j=i;j<10;j++)
  {
   if(a[k]>a[j])
    k=j;
  }
  if(k!=i)
  {
   t=a[k];
   a[k]=a[i];
   a[i]=t;
  }
 }
 
 printf("Sorted Array is:\n");
 for(i=0;i<10;i++)
  printf("%d\n",arr[i]);
 
 return 0;
}

Bubble Sort

/* Bubble Sort */

#include<stdio.h>

int main()
{
 int arr[10],i,j,t;
 printf("Please enter 10 values:\n");
 for(i=0;i<10;i++)
  scanf("%d",&arr[i]);
 
 for(i=0;i<9;i++)
 {
  for(j=0;j<9-i;j++)
  {
   if (arr[j]>arr[j+1])
   {
    t=arr[j];
    arr[j]=arr[j+1];
    arr[j+1]=t;
   }
  }
 }
 
 printf("Sorted Array is:\n");
 for(i=0;i<10;i++)
  printf("%d\n",arr[i]);
 
 return 0;
}

Binary Search

/* Binary Search */

#include<stdio.h>

int main()
{
 int arr[10],i,max,min,mid,val,index;

 printf("Please enter 10 values in ascending order:\n");
 for(i=0;i<10;i++)
  scanf("%d",&arr[i]);
 
 printf("\nEnter a value to be searched: ");
 scanf("%d",&val);
 
 max=9;
 min=0;
 index=-1;
 while(min<=max)
 {
  mid=(max+min)/2;
  if(val==arr[mid])
  {
   index=mid;
   break;
  }
  if(arr[mid]>val)
   max=mid-1;
  else
   min=mid+1;
 }
 
 if(index>=0)
  printf("Value found in Array at %d location",index);
 else
  printf("Value not found in Array");
 return 0;
}

File Copy using command line arguments

/* File Copy using command line arguments */

#include<stdio.h>
int main(int argc,char *argv[])
{
 FILE *fs,*ft;
 int ch;
 if(argc!=3)
 {
  printf("Invalide numbers of arguments.");
  return 1;
 }
 fs=fopen(argv[1],"r");
 if(fs==NULL)
 {
  printf("Can't find the source file.");
  return 1;
 }
 ft=fopen(argv[2],"w");
 if(ft==NULL)
 {
  printf("Can't open target file.");
  fclose(fs);
  return 1;
 }

 while(1)
 {
  ch=fgetc(fs);
  if (feof(fs)) break;
  fputc(ch,ft);
 }

 fclose(fs);
 fclose(ft);
 return 0;
}

File to upper case using command line arguments

/* File to upper case using command line arguments */

#include<stdio.h>
int main(int n,char *a[])
{
 int c;
 FILE *fr,*fw;

 if(n!=3)
 {
  printf("Invalide numbers of arguments.");
  return 1;
 }

 if((fr=fopen(a[1],"r"))==NULL)
 {
  printf("File can't be open.");
  return 1;
 }
 if((fw=fopen(a[2],"r+"))==NULL)
 {
  printf("File can't be open.");
  fclose(fr);
  return 1;
 }
 while(1)
 {
  c=fgetc(fr);
  if(feof(fr)) break;
  c=~c;
  fputc(c,fw);
 }
 fclose(fr);
 fclose(fw);
 return 0;
}

Count characters of file

/* Count characters of file */

#include<stdio.h>
int main()
{
 FILE *fp;
 char a[10];
 long cnt=0;
 int c;

 printf("Type a file name : ");
 gets(a);
 
 if((fp=fopen(a,"r"))==NULL)
  printf("File dosen't exist.");
 else
 {
  while(1)
  {
   c=fgetc(fp);
   if(feof(fp)) break;
   cnt++;
  }
  printf("\nfile have %ld characters",cnt);
 }
 fclose(fp);
 return 0;
}

Write to text file

/* Write to text file */

#include<stdio.h>
int main()
{
 FILE *fp;
 char mystr[100];

 fp=fopen("mytext.txt","w");
 if(fp==NULL)
 {
  puts("Some error occured.");
  return 1;
 }

 printf("\nEnter some lines:\n");
 while(strlen(gets(mystr))>0)
 {
  fputs(mystr,fp);
  fputs("\n",fp);
 }
 fclose(fp);
 return 0;
}

Read text file

/* Read text file */

#include<stdio.h>
int main()
{
 FILE *fp;
 int ch;
 
 fp=fopen("myfile.txt","r");
 if(fp==NULL)
 {
  printf("Can't find the source file.");
  return 1;
 } 
 while(1)
 {
  ch=fgetc(fp);
  if(feof(fp)) break;
  printf("%c",ch);
 } 
 fclose(fp);
 return 0;
}

Towers of Hanoi by recursion

/* Towers of Hanoi by recursion */

#include<stdio.h>
void toh(int,char,char,char);

int main()
{
 int n=3;
 toh(n,'A','B','C');
 return 0;
}

void toh(int n,char a,char b,char c)
{
 if(n==1)
  printf("\nMoved from %c to %c",a,c);
 else
 {
  toh(n-1,a,c,b);
  toh(1,a,' ',c);
  toh(n-1,b,a,c);
 }
}

Binary by recursion

/* Binary by recursion */

#include<stdio.h>
void binary(long);
int main()
{
 long n;
 printf("Type a value : ");
 scanf("%ld",&n);
 binary(n);
 return 0;
}

void binary(long n)
{
 if(n>1)
  binary(n/2);
 printf("%ld",n%2);
}

GCD by Recursion

/* greatest common divisor by recursion */

#include<stdio.h>
int gcd(int,int);

int main()
{
 int a,b;
 printf("Type 2 values to find GCD :\n");
 scanf("%d %d",&a,&b);
 printf("GCD : %d",gcd(a,b));
 return 0;
}

int gcd(int m,int n)
{
 if(n>m) return gcd(n,m);
 if(n==0) return m;
 return gcd(n,m%n);
}

 

Sum of digit by Recursion

/* Sum of digit by recursion */

#include<stdio.h>
int sod(int);

int main()
{
 int i;
 printf(" Type any value : ");
 scanf("%d",&i);
 printf("Sum of digit : %d",sod(i));
 return 0;
}

int sod(int n)
{
 if(n<1)
  return 0;
 return(n%10+sod(n/10));
}

Reverse by Recursion

/* Reverse by Recursion */

#include<stdio.h>
int rev(int,int);

int main()
{
 int a;
 printf("Type a value : ");
 scanf("%d",&a);
 printf("Reverse: %d",rev(a,0));
 return 0;
}

int rev(int i,int r)  
{
 if(i > 0)  
  return rev(i/10,(r*10)+(i%10));  
 return r;  
}

Fibonacci by Recursion

/* Fibonacci by Recursion */

#include<stdio.h>
int fib(int);

int main()
{
 printf("Type any value : ");
 printf("\nNth value: %d",fib(getche()-'0'));
 return 0;
}

int fib(int n)
{
 if(n<=1)
  return n;
 return(fib(n-1)+fib(n-2));
}

Power by Recursion

/* Power by Recursion */

#include<stdio.h>
int pow(int,int);

int main()
{
 int i,j;
 printf("Type two values : \n");
 scanf("%d %d",&i,&j);
 
 printf("i pow j = %d",pow(i,j));
 return 0;
}

int pow(int i,int j)
{
 if(j==1)
  return i;
 return (i*pow(i,j-1));
}