Table of Contents
Practice Programs on Arrays
1. Merge two arrays of same size sorted in descending order:
#include <stdio.h>
void main()
{
int arr1[100], arr2[100], arr3[200];
int s1, s2, s3;
int i, j, k;
printf("\n\nMerge two arrays of same size sorted in decending order.\n");
printf("------------------------------------------------------------\n");
printf("Input the number of elements to be stored in the first array :");
scanf("%d",&s1);
printf("Input %d elements in the array :\n",s1);
for(i=0;i<s1;i++)
{
printf("element - %d : ",i);
scanf("%d",&arr1[i]);
}
printf("Input the number of elements to be stored in the second array :");
scanf("%d",&s2);
printf("Input %d elements in the array :\n",s2);
for(i=0;i<s2;i++)
{
printf("element - %d : ",i);
scanf("%d",&arr2[i]);
}
/* size of merged array is size of first array and size of second array */
s3 = s1 + s2;
/*----------------- insert in the third array------------------------------------*/
for(i=0;i<s1; i++)
{
arr3[i] = arr1[i];
}
for(j=0;j<s2; j++)
{
arr3[i] = arr2[j];
i++;
}
/*----------------- sort the array in decending order ---------------------------*/
for(i=0;i<s3; i++)
{
for(k=0;k<s3-1;k++)
{
if(arr3[k]<=arr3[k+1])
{
j=arr3[k+1];
arr3[k+1]=arr3[k];
arr3[k]=j;
}
}
}
/*--------------- Prints the merged array ------------------------------------*/
printf("\nThe merged array in decending order is :\n");
for(i=0; i<s3; i++)
{
printf("%d ", arr3[i]);
}
printf("\n\n");
}*****************************************************************
2. Count the frequency of each element of an array:
#include <stdio.h>
void main()
{
int arr1[100], fr1[100];
int n, i, j, ctr;
printf("\n\nCount frequency of each element of an array:\n");
printf("------------------------------------------------\n");
printf("Input the number of elements to be stored in the array :");
scanf("%d",&n);
printf("Input %d elements in the array :\n",n);
for(i=0;i<n;i++)
{
printf("element - %d : ",i);
scanf("%d",&arr1[i]);
fr1[i] = -1;
}
for(i=0; i<n; i++)
{
ctr = 1;
for(j=i+1; j<n; j++)
{
if(arr1[i]==arr1[j])
{
ctr++;
fr1[j] = 0;
}
}
if(fr1[i]!=0)
{
fr1[i] = ctr;
}
}
printf("\nThe frequency of all elements of array : \n");
for(i=0; i<n; i++)
{
if(fr1[i]!=0)
{
printf("%d occurs %d times\n", arr1[i], fr1[i]);
}
}
}***************************************************************
3. Sort elements of array in ascending order:
#include <stdio.h>
void main()
{
int arr1[100];
int n, i, j, tmp;
printf("\n\nsort elements of array in ascending order :\n ");
printf("----------------------------------------------\n");
printf("Input the size of array : ");
scanf("%d", &n);
printf("Input %d elements in the array :\n",n);
for(i=0;i<n;i++)
{
printf("element - %d : ",i);
scanf("%d",&arr1[i]);
}
for(i=0; i<n; i++)
{
for(j=i+1; j<n; j++)
{
if(arr1[j] <arr1[i])
{
tmp = arr1[i];
arr1[i] = arr1[j];
arr1[j] = tmp;
}
}
}
printf("\nElements of array in sorted ascending order:\n");
for(i=0; i<n; i++)
{
printf("%d ", arr1[i]);
}
printf("\n\n");
}*******************************************************************
4. Insert New value in the array (sorted list):
#include <stdio.h>
void main()
{
int arr1[100],i,n,p,inval;
printf("\n\nInsert New value in the sorted array :\n");
printf("-----------------------------------------\n");
printf("Input the size of array : ");
scanf("%d", &n);
/* Stored values into the array*/
printf("Input %d elements in the array in ascending order:\n",n);
for(i=0;i<n;i++)
{
printf("element - %d : ",i);
scanf("%d",&arr1[i]);
}
printf("Input the value to be inserted : ");
scanf("%d",&inval);
printf("The exist array list is :\n ");
for(i=0;i<n;i++)
printf("% 5d",arr1[i]);
/* Determine the position where the new value will be insert.*/
for(i=0;i<n;i++)
if(inval<arr1[i]) { p = i; break; } /* move all data at right side of the array */ for(i=n;i>=p;i--)
arr1[i]= arr1[i-1];
/* insert value at the proper position */
arr1[p]=inval;
printf("\n\nAfter Insert the list is :\n ");
for(i=0;i<=n;i++)
printf("% 5d",arr1[i]);
printf("\n");
}************************************************************************
5. Delete an element at desired position from an array:
#include <stdio.h>
void main()
{
int arr1[50],i,pos,n;
printf("\n\nDelete an element at desired position from an array :\n");
printf("---------------------------------------------------------\n");
printf("Input the size of array : ");
scanf("%d", &n);
/* Stored values into the array*/
printf("Input %d elements in the array in ascending order:\n",n);
for(i=0;i<n;i++)
{
printf("element - %d : ",i);
scanf("%d",&arr1[i]);
}
printf("\nInput the position where to delete: ");
scanf("%d",&pos);
/*---- locate the position of i in the array -------*/
i=0;
while(i!=pos-1)
i++;
/*---- the position of i in the array will be replaced by the
value of its right */
while(i<n)
{
arr1[i]=arr1[i+1];
i++;
}
n--;
printf("\nThe new list is : ");
for(i=0;i<n;i++)
{
printf(" %d",arr1[i]);
}
printf("\n\n");
}*********************************************************************
6. Addition of two Matrices:
#include <stdio.h>
void main()
{
int arr1[50][50],brr1[50][50],crr1[50][50],i,j,n;
printf("\n\nAddition of two Matrices :\n");
printf("------------------------------\n");
printf("Input the size of the square matrix (less than 5): ");
scanf("%d", &n);
/* Stored values into the array*/
printf("Input elements in the first matrix :\n");
for(i=0;i<n;i++)
{
for(j=0;j<n;j++)
{
printf("element - [%d],[%d] : ",i,j);
scanf("%d",&arr1[i][j]);
}
}
printf("Input elements in the second matrix :\n");
for(i=0;i<n;i++)
{
for(j=0;j<n;j++)
{
printf("element - [%d],[%d] : ",i,j);
scanf("%d",&brr1[i][j]);
}
}
printf("\nThe First matrix is :\n");
for(i=0;i<n;i++)
{
printf("\n");
for(j=0;j<n;j++)
printf("%d\t",arr1[i][j]);
}
printf("\nThe Second matrix is :\n");
for(i=0;i<n;i++)
{
printf("\n");
for(j=0;j<n;j++)
printf("%d\t",brr1[i][j]);
}
/* calculate the sum of the matrix */
for(i=0;i<n;i++)
for(j=0;j<n;j++)
crr1[i][j]=arr1[i][j]+brr1[i][j];
printf("\nThe Addition of two matrix is : \n");
for(i=0;i<n;i++){
printf("\n");
for(j=0;j<n;j++)
printf("%d\t",crr1[i][j]);
}
printf("\n\n");
}**************************************************************
7. Multiplication of two Matrices:
#include <stdio.h>
void main()
{
int arr1[50][50],brr1[50][50],crr1[50][50],i,j,k,r1,c1,r2,c2,sum=0;
printf("\n\nMultiplication of two Matrices :\n");
printf("----------------------------------\n");
printf("\nInput the rows and columns of first matrix : ");
scanf("%d %d",&r1,&c1);
printf("\nInput the rows and columns of second matrix : ");
scanf("%d %d",&r2,&c2);
if(c1!=r2)
{
printf("Mutiplication of Matrix is not possible.");
printf("\nColumn of first matrix and row of second matrix must be same.");
}
else
{
printf("Input elements in the first matrix :\n");
for(i=0;i<r1;i++)
{
for(j=0;j<c1;j++)
{
printf("element - [%d],[%d] : ",i,j);
scanf("%d",&arr1[i][j]);
}
}
printf("Input elements in the second matrix :\n");
for(i=0;i<r2;i++)
{
for(j=0;j<c2;j++)
{
printf("element - [%d],[%d] : ",i,j);
scanf("%d",&brr1[i][j]);
}
}
printf("\nThe First matrix is :\n");
for(i=0;i<r1;i++)
{
printf("\n");
for(j=0;j<c1;j++)
printf("%d\t",arr1[i][j]);
}
printf("\nThe Second matrix is :\n");
for(i=0;i<r2;i++)
{
printf("\n");
for(j=0;j<c2;j++)
printf("%d\t",brr1[i][j]);
}
//multiplication of matrix
for(i=0;i<r1;i++)
for(j=0;j<c2;j++)
crr1[i][j]=0;
for(i=0;i<r1;i++) //row of first matrix
{
for(j=0;j<c2;j++) //column of second matrix
{
sum=0;
for(k=0;k<c1;k++)
sum=sum+arr1[i][k]*brr1[k][j];
crr1[i][j]=sum;
}
}
printf("\nThe multiplication of two matrices is : \n");
for(i=0;i<r1;i++)
{
printf("\n");
for(j=0;j<c2;j++)
{
printf("%d\t",crr1[i][j]);
}
}
}
printf("\n\n");
}**************************************************************
8. Transpose of a Matrix:
#include <stdio.h>
void main()
{
int arr1[50][50],brr1[50][50],i,j,r,c;
printf("\n\nTranspose of a Matrix :\n");
printf("---------------------------\n");
printf("\nInput the rows and columns of the matrix : ");
scanf("%d %d",&r,&c);
printf("Input elements in the first matrix :\n");
for(i=0;i<r;i++)
{
for(j=0;j<c;j++)
{
printf("element - [%d],[%d] : ",i,j);
scanf("%d",&arr1[i][j]);
}
}
printf("\nThe matrix is :\n");
for(i=0;i<r;i++)
{
printf("\n");
for(j=0;j<c;j++)
printf("%d\t",arr1[i][j]);
}
for(i=0;i<r;i++)
{
for(j=0;j<c;j++)
{
brr1[j][i]=arr1[i][j];
}
}
printf("\n\nThe transpose of a matrix is : ");
for(i=0;i<c;i++)
{
printf("\n");
for(j=0;j<r;j++)
{
printf("%d\t",brr1[i][j]);
}
}
printf("\n\n");
}*******************************************************
9. Find the missing number from a given array:
#include <stdio.h>
int pickMissNumber(int *arr1, int ar_size)
{
int i, sum = 0, n = ar_size + 1;
for(i = 0; i < ar_size; i++)
{
sum = sum + arr1[i];
}
return (n*(n+1))/2 - sum;
}
int main()
{
int i;
int arr1[] = {1, 3, 4, 2, 5, 6, 9, 8};
int ctr = sizeof(arr1)/sizeof(arr1[0]);
printf("The given array is : ");
for(i = 0; i < ctr; i++)
{
printf("%d ", arr1[i]);
}
printf("\n");
printf("The missing number is : %d \n", pickMissNumber(arr1, ctr));
return 0;
}*************************************************************
10. Find two elements whose sum is closest to zero:
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
void findMinSumPair(int *arr1, int arr_size)
{
int i, j, sum, minSum, min1Pair, min2Pair;
if(arr1 == NULL || arr_size < 2)
return;
min1Pair = arr1[0];
min2Pair = arr1[1];
minSum = min1Pair + min2Pair;
for(i = 0; i < arr_size-1; i++)
{
for(j = i+1; j < arr_size; j++)
{
sum = arr1[i] + arr1[j];
if(abs(sum) < abs(minSum))
{
minSum = sum;
min1Pair = arr1[i];
min2Pair = arr1[j];
}
}
}
printf("[%d, %d]\n", min1Pair, min2Pair);
}
int main()
{
int arr1[] = {38, 44, 63, -51, -35, 19, 84, -69, 4, -46};
int ctr = sizeof(arr1)/sizeof(arr1[0]);
int i;
//------------- print original array ------------------
printf("The given array is : ");
for(i = 0; i < ctr; i++)
{
printf("%d ", arr1[i]);
}
printf("\n");
//------------------------------------------------------
printf("The Pair of elements whose sum is minimum are: \n");
findMinSumPair(arr1, ctr);
return 0;
}************************************************
For more practice questions, go to Questionnare.
