C Program for Number System Conversion
C
#include <stdio.h> #include <stdlib.h> #include <string.h> void strrev(char*); // Function to convert decimal to binary and return as a // string char* decimalToBinary(int decimal) { // Allocate space for a 32-bit binary string + '\0' char* binary = (char*)malloc(33); int i = 0; // converting to binary while (decimal) { binary[i++] = '0' + (decimal & 1); decimal >>= 1; } binary[i] = '\0'; strrev(binary); return binary; } // Function to convert binary to decimal and return as an // integer int binaryToDecimal(char binary[]) { int decimal = 0; int length = strlen(binary); for (int i = 0; i < length; i++) { decimal = decimal * 2 + (binary[i] - '0'); } return decimal; } // Function to convert decimal to octal and return as a // string char* decimalToOctal(int decimal) { // Allocate space for an octal string char* octal = (char*)malloc(12); if (octal == NULL) { printf("Memory allocation failed.\n"); exit(1); } // Convert decimal to octal sprintf(octal, "%o", decimal); return octal; } // Function to convert octal to decimal and return as an // integer int octalToDecimal(char octal[]) { int decimal = 0; int length = strlen(octal); for (int i = 0; i < length; i++) { decimal = decimal * 8 + (octal[i] - '0'); } return decimal; } // Function to convert hexadecimal to binary and return as a // string char* hexadecimalToBinary(char hex[]) { // converting hexadecimal string to integer unsigned int hexNum; sscanf(hex, "%x", &hexNum); // string to store binary number char binary[33] = ""; // converting to hexadecimal int i = 0; while (hexNum) { binary[i++] = '0' + hexNum % 2; hexNum /= 2; } binary[i] = '\0'; strrev(binary); return strdup(binary); } // Function to convert binary to hexadecimal and return as a // string char* binaryToHexadecimal(char binary[]) { // Pad the binary string with leading zeros to ensure // it's a multiple of 4 int length = strlen(binary); int padding = (4 - (length % 4)) % 4; char paddedBinary[129]; memset(paddedBinary, '0', padding); strcpy(paddedBinary + padding, binary); // Define a mapping of binary strings to their // hexadecimal representations char* binaryHexDigits[] = { "0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111" }; char hexadecimal[33] = ""; // Allocate space for an // 8-digit hexadecimal string // Iterate through groups of 4 binary digits and convert // to hexadecimal for (int i = 0; i < length + padding; i += 4) { char group[5]; strncpy(group, paddedBinary + i, 4); group[4] = '\0'; // Find the corresponding hexadecimal digit for (int j = 0; j < 16; j++) { if (strcmp(group, binaryHexDigits[j]) == 0) { // Append the corresponding hexadecimal // digit char hexDigit[2]; sprintf(hexDigit, "%X", j); strcat(hexadecimal, hexDigit); break; } } } return strdup(hexadecimal); } // driver code int main() { int choice; while (1) { printf("\nMenu:\n"); printf("1. Decimal to Binary\n"); printf("2. Binary to Decimal\n"); printf("3. Decimal to Octal\n"); printf("4. Octal to Decimal\n"); printf("5. Hexadecimal to Binary\n"); printf("6. Binary to Hexadecimal\n"); printf("7. Exit\n"); printf("Enter your choice: "); scanf("%d", &choice); if (choice == 7) { printf("Goodbye!\n"); break; } char input[100]; // Buffer for user input switch (choice) { case 1: printf("Enter a decimal number: "); scanf("%d", &choice); char* result = decimalToBinary(choice); printf("Decimal to Binary: %s\n", result); free(result); break; case 2: printf("Enter a binary number: "); scanf("%s", input); int binaryResult = binaryToDecimal(input); printf("Binary to Decimal: %d\n", binaryResult); break; case 3: printf("Enter a decimal number: "); scanf("%d", &choice); result = decimalToOctal(choice); printf("Decimal to Octal: %s\n", result); free(result); break; case 4: printf("Enter an octal number: "); scanf("%s", input); int octalResult = octalToDecimal(input); printf("Octal to Decimal: %d\n", octalResult); break; case 5: printf("Enter a hexadecimal number: "); scanf("%s", input); result = hexadecimalToBinary(input); printf("Hexadecimal to Binary: %s\n", result); free(result); break; case 6: printf("Enter a binary number: "); scanf("%s", input); result = binaryToHexadecimal(input); printf("Binary to Hexadecimal: %s\n", result); free(result); break; default: printf("Invalid choice. Please enter a valid " "option.\n"); } } return 0; } // reversing string void strrev(char* str) { int i = 0; int j = strlen(str) - 1; while (i < j) { char c = str[i]; str[i] = str[j]; str[j] = c; i++; j--; } } |
Output
1. Decimal to Binary
Menu: 1. Decimal to Binary 2. Binary to Decimal 3. Decimal to Octal 4. Octal to Decimal 5. Hexadecimal to Binary 6. Binary to Hexadecimal 7. Exit Enter your choice: 1 Enter a decimal number: 128 Decimal to Binary: 10000000
2. Binary to Decimal
Menu: 1. Decimal to Binary 2. Binary to Decimal 3. Decimal to Octal 4. Octal to Decimal 5. Hexadecimal to Binary 6. Binary to Hexadecimal 7. Exit Enter your choice: 2 Enter a binary number: 10000000 Binary to Decimal: 128
3. Decimal to Octal
Menu: 1. Decimal to Binary 2. Binary to Decimal 3. Decimal to Octal 4. Octal to Decimal 5. Hexadecimal to Binary 6. Binary to Hexadecimal 7. Exit Enter your choice: 3 Enter a decimal number: 100 Decimal to Octal: 144
4. Octal to Decimal
Menu: 1. Decimal to Binary 2. Binary to Decimal 3. Decimal to Octal 4. Octal to Decimal 5. Hexadecimal to Binary 6. Binary to Hexadecimal 7. Exit Enter your choice: 4 Enter an octal number: 144 Octal to Decimal: 100
5. Hexadecimal to Binary
Menu: 1. Decimal to Binary 2. Binary to Decimal 3. Decimal to Octal 4. Octal to Decimal 5. Hexadecimal to Binary 6. Binary to Hexadecimal 7. Exit Enter your choice: 5 Enter a hexadecimal number: a10 Hexadecimal to Binary: 101000010000
6. Binary to Hexadecimal
Menu: 1. Decimal to Binary 2. Binary to Decimal 3. Decimal to Octal 4. Octal to Decimal 5. Hexadecimal to Binary 6. Binary to Hexadecimal 7. Exit Enter your choice: 6 Enter a binary number: 101000010000 Binary to Hexadecimal: A10
Number System Conversion in C
Number system conversion is a fundamental concept in computer science and programming. It involves changing the representation of a number from one base to another, such as converting a decimal number to binary or a hexadecimal number to binary.
In this article, we will create a console program in the C language to perform various number system conversions. Our program will be capable of conversion between the following number systems:
- Decimal to Binary
- Binary to Decimal
- Decimal to Octal
- Octal to Decimal
- Hexadecimal to Binary
- Binary to Hexadecimal