C Programming Codes

#include <stdio.h>
#include <stdbool.h>

int main() {
  int rows, cols;

  printf("Enter the number of rows: ");
  scanf("%d", &rows);
  printf("Enter the number of columns: ");
  scanf("%d", &cols);

  int matrix[rows][cols];

  printf("Enter the elements of the matrix:n");
  for (int i = 0; i < rows; i++) {
    for (int j = 0; j < cols; j++) {
      scanf("%d", &matrix[i][j]);
    }
  }

  bool isIdentity = true;

  if (rows != cols) {
    isIdentity = false;
  } else {
    for (int i = 0; i < rows; i++) {
      for (int j = 0; j < cols; j++) {
        if (i == j) {
          if (matrix[i][j] != 1) {
            isIdentity = false;
            break;
          }
        } else {
          if (matrix[i][j] != 0) {
            isIdentity = false;
            break;
          }
        }
      }
      if (!isIdentity) {
        break;
      }
    }
  }

  if (isIdentity) {
    printf("The matrix is an Identity Matrix.n");
  } else {
    printf("The matrix is not an Identity Matrix.n");
  }

  return 0;
}

Input: 3
Input: 3
Input: 1
Input: 0
Input: 0
Input: 0
Input: 1
Input: 0
Input: 0
Input: 0
Input: 1
Output: The matrix is an Identity Matrix.

Input: 2
Input: 2
Input: 1
Input: 0
Input: 0
Input: 2
Output: The matrix is not an Identity Matrix.

Input: 2
Input: 3
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Input: 6
Output: The matrix is not an Identity Matrix.

#include <stdio.h>
#include <stdbool.h>

int main() {
    int rows, cols;

    printf("Enter the number of rows: ");
    scanf("%d", &rows);
    printf("Enter the number of columns: ");
    scanf("%d", &cols);

    if (rows != cols) {
        printf("Matrix is not square, so it cannot be symmetric.n");
        return 0;
    }

    int matrix[rows][cols];

    printf("Enter the elements of the matrix:n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            scanf("%d", &matrix[i][j]);
        }
    }

    bool isSymmetric = true;
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            if (matrix[i][j] != matrix[j][i]) {
                isSymmetric = false;
                break;
            }
        }
        if (!isSymmetric) {
            break;
        }
    }

    if (isSymmetric) {
        printf("The matrix is symmetric.n");
    } else {
        printf("The matrix is not symmetric.n");
    }

    return 0;
}

Input: 3
Input: 3
Input: 1
Input: 2
Input: 3
Input: 2
Input: 4
Input: 5
Input: 3
Input: 5
Input: 6
Output: The matrix is symmetric.

Input: 2
Input: 3
Output: Matrix is not square, so it cannot be symmetric.

Input: 2
Input: 2
Input: 1
Input: 2
Input: 3
Input: 4
Output: The matrix is not symmetric.

#include <stdio.h>

int main() {
    int rows, cols;
    printf("Enter the number of rows: ");
    scanf("%d", &rows);
    printf("Enter the number of columns: ");
    scanf("%d", &cols);

    if (rows != cols) {
        printf("Matrix must be square for secondary diagonal sum.n");
        return 1;
    }

    int matrix[rows][cols];
    printf("Enter the elements of the matrix:n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            scanf("%d", &matrix[i][j]);
        }
    }

    int sum = 0;
    for (int i = 0; i < rows; i++) {
        sum += matrix[i][cols - 1 - i];
    }

    printf("Sum of secondary diagonal elements: %dn", sum);

    return 0;
}

Input: 3
Input: 3
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Input: 6
Input: 7
Input: 8
Input: 9
Output: Sum of secondary diagonal elements: 15

Input: 2
Input: 4
Output: Matrix must be square for secondary diagonal sum.

#include <stdio.h>

int main() {
    int rows, cols, i, j, sum = 0;

    printf("Enter the number of rows: ");
    scanf("%d", &rows);
    printf("Enter the number of columns: ");
    scanf("%d", &cols);

    if (rows != cols) {
        printf("Matrix must be square to calculate the sum of the main diagonal.n");
        return 1;
    }

    int matrix[rows][cols];

    printf("Enter the elements of the matrix:n");
    for (i = 0; i < rows; i++) {
        for (j = 0; j < cols; j++) {
            scanf("%d", &matrix[i][j]);
        }
    }

    for (i = 0; i < rows; i++) {
        sum = sum + matrix[i][i]; // Add the diagonal element to sum
    }

    printf("Sum of main diagonal elements: %dn", sum);

    return 0;
}

Input: 3
Input: 3
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Input: 6
Input: 7
Input: 8
Input: 9
Output: Sum of main diagonal elements: 15

Input: 2
Input: 4
Output: Matrix must be square to calculate the sum of the main diagonal.

#include <stdio.h>

int main() {
    int rows, cols, i, j;

    printf("Enter the number of rows: ");
    scanf("%d", &rows);
    printf("Enter the number of columns: ");
    scanf("%d", &cols);

    int matrix[rows][cols], transpose[cols][rows];

    printf("Enter the elements of the matrix:n");
    for (i = 0; i < rows; i++) {
        for (j = 0; j < cols; j++) {
            scanf("%d", &matrix[i][j]);
        }
    }

    for (i = 0; i < rows; i++) {
        for (j = 0; j < cols; j++) {
            transpose[j][i] = matrix[i][j];
        }
    }

    printf("Transpose of the matrix:n");
    for (i = 0; i < cols; i++) {
        for (j = 0; j < rows; j++) {
            printf("%d ", transpose[i][j]);
        }
        printf("n");
    }

    return 0;
}

Input: 2
Input: 3
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Input: 6
Output: Enter the number of rows: Enter the number of columns: Enter the elements of the matrix:
Transpose of the matrix:
1 4
2 5
3 6

#include <stdio.h>

int main() {
  int row1, col1, row2, col2;

  printf("Enter the number of rows and columns for the first matrix: ");
  scanf("%d %d", &row1, &col1);

  printf("Enter the number of rows and columns for the second matrix: ");
  scanf("%d %d", &row2, &col2);

  if (col1 != row2) {
    printf("Matrices cannot be multiplied.n");
    return 1;
  }

  int matrix1[row1][col1], matrix2[row2][col2], result[row1][col2];
  int i, j, k;

  printf("Enter the elements of the first matrix:n");
  for (i = 0; i < row1; i++) {
    for (j = 0; j < col1; j++) {
      scanf("%d", &matrix1[i][j]);
    }
  }

  printf("Enter the elements of the second matrix:n");
  for (i = 0; i < row2; i++) {
    for (j = 0; j < col2; j++) {
      scanf("%d", &matrix2[i][j]);
    }
  }

  for (i = 0; i < row1; i++) {
    for (j = 0; j < col2; j++) {
      result[i][j] = 0;
      for (k = 0; k < col1; k++) {
        result[i][j] += matrix1[i][k] * matrix2[k][j];
      }
    }
  }

  printf("Resultant matrix:n");
  for (i = 0; i < row1; i++) {
    for (j = 0; j < col2; j++) {
      printf("%d ", result[i][j]);
    }
    printf("n");
  }

  return 0;
}

Input: 2 2
Input: 2 2
Input: 1 2
Input: 3 4
Input: 5 6
Input: 7 8
Output: Enter the number of rows and columns for the first matrix: Enter the number of rows and columns for the second matrix: Enter the elements of the first matrix:
Enter the elements of the second matrix:
Resultant matrix:
19 22
43 50

#include <stdio.h>

int main() {
    int rows, cols;

    printf("Enter the number of rows: ");
    scanf("%d", &rows);
    printf("Enter the number of columns: ");
    scanf("%d", &cols);

    int matrix1[rows][cols], matrix2[rows][cols], result[rows][cols];

    printf("Enter elements of the first matrix:n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            scanf("%d", &matrix1[i][j]);
        }
    }

    printf("Enter elements of the second matrix:n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            scanf("%d", &matrix2[i][j]);
        }
    }

    // Subtract the matrices
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            result[i][j] = matrix1[i][j] - matrix2[i][j];
        }
    }

    printf("Resultant matrix after subtraction:n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%d ", result[i][j]);
        }
        printf("n");
    }

    return 0;
}

Input: 2
Input: 2
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Input: 6
Input: 7
Input: 8
Output: Enter the number of rows: Enter the number of columns: Enter elements of the first matrix:
Enter elements of the second matrix:
Resultant matrix after subtraction:
-4 -4
-4 -4

#include <stdio.h>

int main() {
    int rows, cols;

    printf("Enter the number of rows: ");
    scanf("%d", &rows);
    printf("Enter the number of columns: ");
    scanf("%d", &cols);

    int matrix1[rows][cols], matrix2[rows][cols], sum[rows][cols];

    printf("Enter elements of the first matrix:n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            scanf("%d", &matrix1[i][j]);
        }
    }

    printf("Enter elements of the second matrix:n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            scanf("%d", &matrix2[i][j]);
        }
    }

    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            sum[i][j] = matrix1[i][j] + matrix2[i][j];
        }
    }

    printf("Sum of the matrices:n");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("%d ", sum[i][j]);
        }
        printf("n");
    }

    return 0;
}

Input: 2
Input: 3
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Input: 6
Input: 7
Input: 8
Input: 9
Input: 10
Input: 11
Input: 12
Output: Enter the number of rows: Enter the number of columns: Enter elements of the first matrix:
Enter elements of the second matrix:
Sum of the matrices:
8 10 12
14 16 18

#include <stdio.h>

int main() {
    int arr[100];
    int n, i, target, count = 0;

    printf("Enter the number of elements in the array: ");
    scanf("%d", &n);

    printf("Enter the elements of the array:n");
    for (i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    printf("Enter the element to count: ");
    scanf("%d", &target);

    for (i = 0; i < n; i++) {
        if (arr[i] == target) {
            count++;
        }
    }

    printf("The element %d occurs %d times in the array.n", target, count);

    return 0;
}

Input: 5
Input: 1
Input: 2
Input: 2
Input: 3
Input: 2
Input: 2
Output: Enter the number of elements in the array: Enter the elements of the array:
Enter the element to count: The element 2 occurs 3 times in the array.

#include <stdio.h>
#include <stdbool.h>

bool isPrime(int n) {
  if (n <= 1) return false;
  for (int i = 2; i * i <= n; i++) {
    if (n % i == 0) return false;
  }
  return true;
}

int main() {
  int size;

  printf("Enter the size of the array: ");
  scanf("%d", &size);

  int arr[size];

  printf("Enter the elements of the array: ");
  for (int i = 0; i < size; i++) {
    scanf("%d", &arr[i]);
  }

  printf("Prime numbers in the array are: ");
  for (int i = 0; i < size; i++) {
    if (isPrime(arr[i])) {
      printf("%d ", arr[i]);
    }
  }
  printf("n");

  return 0;
}

Input: 5
Input: 1 2 3 4 5
Output: Enter the size of the array: Enter the elements of the array: Prime numbers in the array are: 2 3 5

#include <stdio.h>

int main() {
  int arr[100];
  int even[100];
  int odd[100];
  int n, i, even_count = 0, odd_count = 0;

  printf("Enter the number of elements in the array: ");
  scanf("%d", &n);

  printf("Enter the elements of the array:n");
  for (i = 0; i < n; i++) {
    scanf("%d", &arr[i]);
  }

  for (i = 0; i < n; i++) {
    if (arr[i] % 2 == 0) {
      even[even_count] = arr[i];
      even_count++;
    } else {
      odd[odd_count] = arr[i];
      odd_count++;
    }
  }

  printf("Even numbers in the array are:n");
  for (i = 0; i < even_count; i++) {
    printf("%d ", even[i]);
  }
  printf("n");

  printf("Odd numbers in the array are:n");
  for (i = 0; i < odd_count; i++) {
    printf("%d ", odd[i]);
  }
  printf("n");

  return 0;
}

Input: 5
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Output: Enter the number of elements in the array: Enter the elements of the array:
Even numbers in the array are:
2 4
Odd numbers in the array are:
1 3 5

#include <stdio.h>

int main() {
    int arr[100];
    int n, i, j;

    printf("Enter the number of elements in the array: ");
    scanf("%d", &n);

    printf("Enter the elements of the array:n");
    for (i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    int mode = arr[0];
    int maxCount = 1;

    for (i = 0; i < n; i++) {
        int count = 1;
        for (j = i + 1; j < n; j++) {
            if (arr[i] == arr[j]) {
                count++;
            }
        }
        if (count > maxCount) {
            maxCount = count;
            mode = arr[i];
        }
    }

    printf("Mode of the array is: %dn", mode);

    return 0;
}

Input: 5
Input: 1
Input: 2
Input: 2
Input: 3
Input: 2
Output: Mode of the array is: 2

Input: 7
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Input: 6
Input: 7
Output: Mode of the array is: 1

Input: 6
Input: 5
Input: 5
Input: 5
Input: 1
Input: 2
Input: 3
Output: Mode of the array is: 5

Input: 4
Input: 2
Input: 2
Input: 1
Input: 1
Output: Mode of the array is: 2

#include <stdio.h>
#include <stdlib.h>

int main() {
    int n;
    printf("Enter the number of elements in the array: ");
    scanf("%d", &n);

    int arr[n];
    printf("Enter the elements of the array:n");
    for (int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    // Sort the array (using bubble sort for simplicity)
    for (int i = 0; i < n - 1; i++) {
        for (int j = 0; j < n - i - 1; j++) {
            if (arr[j] > arr[j + 1]) {
                int temp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = temp;
            }
        }
    }

    float median;
    if (n % 2 == 0) {
        // If the number of elements is even
        median = (float)(arr[n / 2 - 1] + arr[n / 2]) / 2;
    } else {
        // If the number of elements is odd
        median = (float)arr[n / 2];
    }

    printf("The median of the array is: %.2fn", median);

    return 0;
}

Input: 5
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Output: The median of the array is: 3.00

Input: 6
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Input: 6
Output: The median of the array is: 3.50

#include <stdio.h>

int main() {
    int n, i;
    long long product = 1;

    printf("Enter the number of elements in the array: ");
    scanf("%d", &n);

    int arr[n];

    printf("Enter the elements of the array:n");
    for (i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    for (i = 0; i < n; i++) {
        product *= arr[i];
    }

    printf("Product of all elements in the array = %lldn", product);

    return 0;
}

Input: 5
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Output: Product of all elements in the array = 120

#include <stdio.h>

int main() {
  int n;
  printf("Enter the size of the array: ");
  scanf("%d", &n);

  int arr[n];
  printf("Enter the elements of the array:n");
  for (int i = 0; i < n; i++) {
    scanf("%d", &arr[i]);
  }

  int cumulative_sum[n];
  cumulative_sum[0] = arr[0];

  for (int i = 1; i < n; i++) {
    cumulative_sum[i] = cumulative_sum[i - 1] + arr[i];
  }

  printf("Cumulative sum of the array:n");
  for (int i = 0; i < n; i++) {
    printf("%d ", cumulative_sum[i]);
  }
  printf("n");

  return 0;
}

Input: 5
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Output: Enter the size of the array: Enter the elements of the array:
Cumulative sum of the array:
1 3 6 10 15

#include <stdio.h>

int main() {
  int arr[100];
  int n, i, positiveCount = 0, negativeCount = 0;

  printf("Enter the number of elements in the array: ");
  scanf("%d", &n);

  printf("Enter the elements of the array:n");
  for (i = 0; i < n; i++) {
    scanf("%d", &arr[i]);
  }

  for (i = 0; i < n; i++) {
    if (arr[i] > 0) {
      positiveCount++;
    } else if (arr[i] < 0) {
      negativeCount++;
    }
  }

  printf("Positive numbers: %dn", positiveCount);
  printf("Negative numbers: %dn", negativeCount);

  return 0;
}

Input: 5
Input: 1
Input: -2
Input: 3
Input: -4
Input: 0
Output: Enter the number of elements in the array: Enter the elements of the array:
Positive numbers: 2
Negative numbers: 2

#include <stdio.h>

int main() {
    int arr[100];
    int n, i, evenCount = 0, oddCount = 0;

    printf("Enter the number of elements in the array: ");
    scanf("%d", &n);

    printf("Enter the elements of the array:n");
    for (i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    for (i = 0; i < n; i++) {
        if (arr[i] % 2 == 0) {
            evenCount++;
        } else {
            oddCount++;
        }
    }

    printf("Even numbers: %dn", evenCount);
    printf("Odd numbers: %dn", oddCount);

    return 0;
}

Input: 5
Input: 1
Input: 2
Input: 3
Input: 4
Input: 5
Output: Even numbers: 2
Output: Odd numbers: 3

#include <stdio.h>
#include <limits.h>

int main() {
    int n, i;

    printf("Enter the number of elements in the array: ");
    scanf("%d", &n);

    int arr[n];

    printf("Enter the elements of the array:n");
    for (i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    int smallest = INT_MAX;
    int secondSmallest = INT_MAX;

    for (i = 0; i < n; i++) {
        if (arr[i] < smallest) {
            secondSmallest = smallest;
            smallest = arr[i];
        } else if (arr[i] < secondSmallest && arr[i] != smallest) {
            secondSmallest = arr[i];
        }
    }

    if (secondSmallest == INT_MAX) {
        printf("There is no second smallest element.n");
    } else {
        printf("The second smallest element is: %dn", secondSmallest);
    }

    return 0;
}

Input: 5
Input: 5
Input: 2
Input: 8
Input: 1
Input: 9
Output: The second smallest element is: 2

Input: 4
Input: 1
Input: 1
Input: 1
Input: 1
Output: There is no second smallest element.

Input: 3
Input: 10
Input: 5
Input: 10
Output: The second smallest element is: 10

Input: 2
Input: 7
Input: 3
Output: The second smallest element is: 7

#include <stdio.h>

int main() {
    int n, i, largest, secondLargest;

    printf("Enter the number of elements in the array: ");
    scanf("%d", &n);

    int arr[n];

    printf("Enter the elements of the array:n");
    for (i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }

    if (n < 2) {
        printf("Array should have at least two elements.n");
        return 0;
    }

    largest = arr[0];
    secondLargest = arr[1];

    if (secondLargest > largest) {
        int temp = largest;
        largest = secondLargest;
        secondLargest = temp;
    }

    for (i = 2; i < n; i++) {
        if (arr[i] > largest) {
            secondLargest = largest;
            largest = arr[i];
        } else if (arr[i] > secondLargest && arr[i] != largest) {
            secondLargest = arr[i];
        }
    }

    if (largest == secondLargest) {
        printf("There is no second largest element as all elements are the same.n");
    } else {
        printf("The second largest element in the array is: %dn", secondLargest);
    }

    return 0;
}

Input: 5
Input: 10
Input: 5
Input: 8
Input: 2
Input: 7
Output: The second largest element in the array is: 8

Input: 3
Input: 5
Input: 5
Input: 5
Output: There is no second largest element as all elements are the same.

Input: 1
Output: Enter the number of elements in the array: Array should have at least two elements.

Input: 2
Input: 1
Input: 2
Output: The second largest element in the array is: 1