Program 1: Write a program to copy the contents of one array into another in the reverse order.

Code:
#include<stdio.h>

int main()

{ int arry1[10],arry2[10]={0},i,j;

printf("Enter the elements of array: \n"); for(i=0;i<10;i++)

{ printf("Enter element %d:",i+1); scanf("%d",&arry1[i]);

}

i=0; for(j=9;j>=0;j--) {

arry2[j]=arry1[i]; i+=1;

}

printf("Array elements in reverse order are: \n"); for(i=0;i<10;i++)

{ printf("element %d:%d \n",i+1,arry2[i]); }

return(0);

}

Output:

Program 2: If an array arr contains n elements, then write a program to check if arr[0] = arr[n-1], arr[1] = arr[n-2] and so on.
Code:
#include<stdio.h>

int main()

{ int arry1[10],i,j,k=0;

printf("Enter the 10 elements of array: \n"); for(i=0;i<10;i++)

{ printf("Enter element %d:",i+1); scanf("%d",&arry1[i]);

}

j=9; for(i=0;i<5;i++)

{ if(arry1[i]==arry1[j]) { printf("Elemets %d and %d are same \n", i+1,j+1); k=1; } j--; } if(k==0) { printf("No match found\n"); } return(0);

}

Output:

Program 3: Find the smallest number in an array using pointers.

Code:
#include<stdio.h>

int main()

{ int arry1[10],i,*j,k=10000;

printf("Enter the 10 elements of array: \n"); for(i=0;i<10;i++)

{ printf("Enter element %d:",i+1); scanf("%d",&arry1[i]);

}

j=&arry1[0];

for(i=0;i<9;i++)

{ if(*j<k) { k=*j; } j++; } printf("The smallest number is: %d\n", k); return(0);

}

Output:

Program 4: Write a program which performs the following tasks:
i. initialize an integer array of 10 elements in main( ) ii. pass the entire array to a function modify( ) iii. in modify( )multiply each element of array by 3 iv. return the control to main( )and print the new array elements in main( )

Code:
#include<stdio.h>
int modify(int *j);

int main()

{ int arry1[10],i,*j;

printf("Enter the 10 elements of array: \n"); for(i=0;i<10;i++)

{ printf("Enter element %d:",i+1); scanf("%d",&arry1[i]);

}

j=&arry1[0]; modify(j); for(i=0;i<10;i++)

{ printf("The new array element %d is: %d\n",i+1,*j); j=j+1; } }

int modify(int *j) { int i; for(i=0;i<10;i++) { *j=*j*3; j=j+1; } return(0); }

Output:

Program 5: Write a program to pick up the largest number from any 5 row by 5 column matrix.

Code:
#include<stdio.h>

int main()

{ int a[5][5],i,j,k=-10000;

printf("Enter 5 row by 5 column matrix: \n");

for(i=0;i<5;i++)

{ for(j=0;j<5;j++) { printf("Enter element a[%d][%d]:",i+1,j+1); scanf("%d", &a[i][j]); if(a[i][j]>k) k=a[i][j]; } }

printf("The largest number is: %d\n", k); return(0);
}

Output:

Program 6: For the following set of n data points (x, y), compute the correlation coefficient r, given by x y
34.22 102.43
39.87 100.93
41.85 97.43
43.23 97.81
40.06 98.32
53.29 98.32
53.29 100.07
54.14 97.08
49.12 91.59
40.71 94.85
55.15 94.65

Code:
#include<stdio.h>
#include<math.h>

int main()

{ float x[11]={34.22,39.87,41.85,43.23,40.06,53.29,53.29,54.14,49.12,40.71,55.15},y[11]={102.43,100.93,97.43,97.81,98.32,98.32,100.07,97.08,91.59,94.85,94.65},sumx=0,sumy=0,sumxy=0,sumx2=0,sumy2=0,temp,r; int i,j; for(i=0;i<11;i++) { sumx=sumx+x[i]; } for(i=0;i<11;i++) { sumy=sumy+y[i]; } for(i=0;i<11;i++) { temp=x[i]*y[i]; sumxy=temp+sumxy; } for(i=0;i<11;i++) { temp=x[i]*x[i]; sumx2=temp+sumx2; } for(i=0;i<11;i++) { temp=y[i]*y[i]; sumy2=temp+sumy2; } temp=(11*sumx2-(sumx*sumx))*(11*sumy2-(sumy*sumy)); r=(sumxy-(sumx*sumy))/sqrt(temp); printf("Correlelation coffecient is: %f", r); return(0); }

Output:

Problem 7: Write a program to multiply any two 3 x 3 matrices.

Code:

#include<stdio.h>

int main()

{ int a[3][3],b[3][3],c[3][3],i,j,k,g,sum=0; printf("Enter elements of 1st matrix: \n");

for(i=0;i<3;i++)

{ for(j=0;j<3;j++) { printf("Enter element a[%d][%d]:",i+1,j+1); scanf("%d", &a[i][j]); } }

printf("Enter elements of 2nd matrix: \n"); for(i=0;i<3;i++)

{ for(j=0;j<3;j++) { printf("Enter element a[%d][%d]:",i+1,j+1); scanf("%d", &b[i][j]); } }

for(i=0;i<3;i++)
{
for(j=0;j<3;j++) { for(k=0;k<3;k++) { g=a[i][k]*b[k][j]; sum=sum+g; } c[i][j]=sum; sum=0; }
}

printf("Multiplication of two matrix is: \n");

for(i=0;i<3;i++)

{ printf("\n \n");

for(j=0;j<3;j++) { printf(" %d \t", c[i][j]);

} } printf("\n");

return(0);

}

Output:

Problem 8: Write a program to sort all the elements of a 4 x 4 matrix.

Code:
#include<stdio.h>

int main()

{ int a[4][4],i,j,temp,k,l; int *ptr; ptr=&a[0][0];

printf("Enter elements of 4x4 matrix: \n");

for(i=0;i<4;i++)

{ for(j=0;j<4;j++) { printf("Enter element a[%d][%d]:",i+1,j+1); scanf("%d", &a[i][j]); } }

for(k=0;k<16;k++)
{
ptr=&a[0][0]; for(l=0;l<16;l++) {

if(*ptr>*(ptr+1)) { temp=*(ptr+1); *(ptr+1)=*ptr; *ptr=temp; } ptr++; }
}

printf("Sorted matrix is: \n");

for(i=0;i<4;i++)

{ printf("\n \n");

for(j=0;j<4;j++) { printf(" %d \t", a[i][j]);

} } printf("\n"); return(0); }

Output:

Problem 10: Write a function to find the norm of a matrix. The norm is defined as the square root of the sum of squares of all elements in the matrix.

Code:
#include<stdio.h>
#include<math.h> float nrma(int a[100][100],int n,int m);

int main()

{ int a[100][100]={0},i,j,m,n; float ans; printf("Enter number of rows between 1-100: \n"); scanf("%d", &n); do { if(n>100) { printf("Error! number should be in range of 1-100: \n"); printf("Enter the number again: \n"); scanf("%d", &n); } else if(n<=100) break; }while(1);

printf("Enter number of columns in range of 1-100: \n"); scanf("%d", &m); do { if(m>100) { printf("Error! number should be in range of 1-100: \n"); printf("Enter the number again: \n"); scanf("%d", &m); } else if(m<=100) break; }while(1);

printf("Enter elements of matrix: \n");

for(i=0;i<n;i++)

{ for(j=0;j<m;j++) { printf("Enter element a[%d][%d]:",i+1,j+1); scanf("%d", &a[i][j]); } } ans=nrma(a,n,m); printf("The norm of matrix is: %f", ans);

}

float nrma(int a[100][100],int n,int m)

{ int i,j,sum=0,sum1=0,k; float ans; for(i=0;i<n;i++)
{
for(j=0;j<m;j++) { k=a[i][j]*a[i][j]; sum=k+sum; } sum1=sum+sum1; sum=0;
}

ans=sqrt(sum1); return(ans); }

Output: