Explain the concept of one and two dimensional array processing using C language

Arrays in C programming are collections of elements of the same data type stored in contiguous memory locations. Array processing involves operations like reading, writing, and manipulating array elements. Let us explore one-dimensional and two-dimensional array processing.

Syntax

/* 1D Array Declaration */
datatype array_name[size];

/* 2D Array Declaration */
datatype array_name[rows][columns];

1D Array Processing

One-dimensional arrays store elements in a linear sequence. Here's how to read and write elements −

Reading Elements into 1D Array

int num[5];
int i;
for(i=0; i<5; i++){
    scanf("%d", &num[i]);
}

Writing Elements from 1D Array

int num[5];
int i;
for(i=0; i<5; i++){
    printf("%d ", num[i]);
}

Example: Reverse Order Display

The following program reads elements into an array and displays them in reverse order −

#include <stdio.h>

int main() {
    int array[5], i;
    
    printf("Enter 5 elements: ");
    for(i = 0; i < 5; i++) {
        scanf("%d", &array[i]);
    }
    
    printf("Elements in reverse order: ");
    for(i = 4; i >= 0; i--) {
        printf("%d ", array[i]);
    }
    printf("<br>");
    
    return 0;
}

Enter 5 elements: 1 2 3 4 5
Elements in reverse order: 5 4 3 2 1 

2D Array Processing

Two-dimensional arrays store elements in a matrix format with rows and columns −

Reading Elements into 2D Array

int a[4][3];
int i, j;
for(i = 0; i < 4; i++) {
    for(j = 0; j < 3; j++) {
        scanf("%d", &a[i][j]);
    }
}

Writing Elements from 2D Array

int a[4][3];
int i, j;
for(i = 0; i < 4; i++) {
    for(j = 0; j < 3; j++) {
        printf("%d ", a[i][j]);
    }
    printf("<br>");
}

Example: Matrix Addition and Multiplication

The following program demonstrates addition and element-wise multiplication of two matrices −

#include <stdio.h>

int main() {
    int A[2][3] = {{2, 3, 4}, {1, 2, 3}};
    int B[2][3] = {{4, 5, 3}, {2, 1, 2}};
    int sum[2][3], product[2][3];
    int i, j;
    
    /* Calculate sum and product */
    for(i = 0; i < 2; i++) {
        for(j = 0; j < 3; j++) {
            sum[i][j] = A[i][j] + B[i][j];
            product[i][j] = A[i][j] * B[i][j];
        }
    }
    
    printf("Matrix A:<br>");
    for(i = 0; i < 2; i++) {
        for(j = 0; j < 3; j++) {
            printf("%d ", A[i][j]);
        }
        printf("<br>");
    }
    
    printf("\nMatrix B:<br>");
    for(i = 0; i < 2; i++) {
        for(j = 0; j < 3; j++) {
            printf("%d ", B[i][j]);
        }
        printf("<br>");
    }
    
    printf("\nSum Matrix:<br>");
    for(i = 0; i < 2; i++) {
        for(j = 0; j < 3; j++) {
            printf("%d ", sum[i][j]);
        }
        printf("<br>");
    }
    
    printf("\nProduct Matrix:<br>");
    for(i = 0; i < 2; i++) {
        for(j = 0; j < 3; j++) {
            printf("%d ", product[i][j]);
        }
        printf("<br>");
    }
    
    return 0;
}

Matrix A:
2 3 4 
1 2 3 

Matrix B:
4 5 3 
2 1 2 

Sum Matrix:
6 8 7 
3 3 5 

Product Matrix:
8 15 12 
2 2 6 

Conclusion

Array processing in C involves systematic reading, writing, and manipulation of elements using loops. One-dimensional arrays handle linear data, while two-dimensional arrays manage matrix-like data structures efficiently.