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  1. #include <stdio.h>
  2. #include <stdbool.h>
  3.  
  4. int main() {
  5.     long long num; 
  6.     int base;      
  7.  
  8.     printf("Enter the number to convert: ");
  9.     scanf("%lld", &num);
  10.  
  11.     printf("Enter the base of the number (e.g., 2 for binary, 8 for octal): ");
  12.     scanf("%d", &base);
  13.  
  14.     long long decimalValue = 0;
  15.     long long power = 1; 
  16.  
  17.     bool isNegative = false;
  18.     if (num < 0) {
  19.         isNegative = true;
  20.         num = -num; 
  21.     }
  22.  
  23.     while (num > 0) {
  24.         int digit = num % 10; 
  25.  
  26.         if (digit >= base) {
  27.             printf("Error: Invalid digit '%d' for base %d\n", digit, base);
  28.             return 1; 
  29.         }
  30.  
  31.         decimalValue += digit * power; 
  32.         power *= base;                 
  33.         num /= 10;                    
  34.     }
  35.  
  36.     if (isNegative) {
  37.         decimalValue = -decimalValue;
  38.     }
  39.  
  40.     printf("The decimal equivalent is: %lld\n", decimalValue);
  41.  
  42.     return 0;
  43. }
Success #stdin #stdout 0s 5288KB
comments (?)
stdin 
Standard input is empty
stdout 
Enter the number to convert: Enter the base of the number (e.g., 2 for binary, 8 for octal): The decimal equivalent is: 4792977702598085758
https://ideone.com/9wpdhw
language:
C (gcc 8.3)
created:
2 days ago
visibility:
public

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