Experiment No.2 Implement a C program to convert a Hexadecimal, octal, and binary number vice versa.

index.c

// Name: Ayush Kumar Jha
// Enrollment Number: 2022-350-009
// Subject: Computer Organisation and Architecture + Operating System B.Tech CSE AI 406
// Experiment No. 2   Implement a C program to convert a Hexadecimal, octal, and binary number vice versa.

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

// Function to convert hexadecimal to decimal
int hexToDecimal(char hex[]) {
    int len = strlen(hex);
    int decimal = 0;
    int base = 1;

    for (int i = len - 1; i >= 0; i--) {
        int digit;
        if (hex[i] >= '0' && hex[i] <= '9') {
            digit = hex[i] - '0';
        } else if (hex[i] >= 'A' && hex[i] <= 'F') {
            digit = hex[i] - 'A' + 10;
        } else if (hex[i] >= 'a' && hex[i] <= 'f') {
            digit = hex[i] - 'a' + 10;
        } else {
            printf("Invalid hexadecimal number\n");
            return -1;
        }
        decimal += digit * base;
        base *= 16;
    }

    return decimal;
}

// Function to convert decimal to hexadecimal
void decimalToHex(int decimal) {
    char hex[20];
    int i = 0;

    while (decimal != 0) {
        int remainder = decimal % 16;
        if (remainder < 10)
            hex[i++] = remainder + 48;
        else
            hex[i++] = remainder + 55;
        decimal = decimal / 16;
    }

    printf("Hexadecimal: ");
    for (int j = i - 1; j >= 0; j--) {
        printf("%c", hex[j]);
    }
    printf("\n");
}

// Function to convert octal to decimal
int octalToDecimal(int octal) {
    int decimal = 0, i = 0;

    while (octal != 0) {
        decimal += (octal % 10) * (1 << (3*i));
        ++i;
        octal /= 10;
    }

    return decimal;
}

// Function to convert decimal to octal
int decimalToOctal(int decimal) {
    int octal = 0, i = 1;

    while (decimal != 0) {
        octal += (decimal % 8) * i;
        decimal /= 8;
        i *= 10;
    }

    return octal;
}

// Function to convert binary to decimal
int binaryToDecimal(long long binary) {
    int decimal = 0, i = 0;

    while (binary != 0) {
        decimal += (binary % 10) * pow(2, i);
        ++i;
        binary /= 10;
    }

    return decimal;
}

// Function to convert decimal to binary
long long decimalToBinary(int decimal) {
    long long binary = 0;
    int remainder, i = 1;

    while (decimal != 0) {
        remainder = decimal % 2;
        decimal /= 2;
        binary += remainder * i;
        i *= 10;
    }

    return binary;
}

int main() {
    int choice, decimal, number;
    long long binary;
    char hex[20];

    printf("Choose conversion:\n");
    printf("1. Hexadecimal to Decimal\n");
    printf("2. Decimal to Hexadecimal\n");
    printf("3. Octal to Decimal\n");
    printf("4. Decimal to Octal\n");
    printf("5. Binary to Decimal\n");
    printf("6. Decimal to Binary\n");
    printf("Enter your choice: ");
    scanf("%d", &choice);

    switch(choice) {
        case 1:
            printf("Enter a hexadecimal number: ");
            scanf("%s", hex);
            decimal = hexToDecimal(hex);
            if (decimal != -1) {
                printf("Decimal: %d\n", decimal);
            }
            break;
        case 2:
            printf("Enter a decimal number: ");
            scanf("%d", &decimal);
            decimalToHex(decimal);
            break;
        case 3:
            printf("Enter an octal number: ");
            scanf("%o", &number);
            printf("Decimal: %d\n", octalToDecimal(number));
            break;
        case 4:
            printf("Enter a decimal number: ");
            scanf("%d", &number);
            printf("Octal: %o\n", decimalToOctal(number));
            break;
        case 5:
            printf("Enter a binary number: ");
            scanf("%lld", &binary);
            printf("Decimal: %d\n", binaryToDecimal(binary));
            break;
        case 6:
            printf("Enter a decimal number: ");
            scanf("%d", &decimal);
            printf("Binary: %lld\n", decimalToBinary(decimal));
            break;
        default:
            printf("Invalid choice!\n");
    }

    return 0;
}