# C Program to Convert Octal to Decimal

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This is a C program to convert octal number to decimal.

Problem Description

This program takes a octal number as input and converts it into decimal number.

Problem Solution

1. Take a octal number as input.
2. Multiply each digits of the octal number starting from the last with the powers of 8 respectively.
3. Add all the multiplied digits.
4. The total sum gives the decimal number.

Program/Source Code

Here is source code of the C program to Convert Octal to Decimal. The C program is successfully compiled and run on a Linux system. The program output is also shown below.

1. `/*`
2. ` * C Program to Convert Octal to Decimal`
3. ` */`
4. `#include <stdio.h>`
5. `#include <math.h>`
6. ` `
7. `int main()`
8. `{`
9. ` `
10. `    long int octal, decimal = 0;`
11. `    int i = 0;`
12. ` `
13. `    printf("Enter any octal number: ");`
14. `    scanf("%ld", &octal);`
15. `    while (octal != 0)`
16. `    {`
17. `        decimal =  decimal +(octal % 10)* pow(8, i++);`
18. `        octal = octal / 10;`
19. `    }`
20. `    printf("Equivalent decimal value: %ld",decimal);`
21. `    return 0;`
22. `}`
Program Explanation

1. Take the octal number as input and store it in the variable octal.
2. Initialize the variables decimal and i to zero.
3. Obtain the remainder and quotient of the octal number. Multiply the remainder by powers of 8 using function pow(8, i++), add this value to the variable decimal and store it in the variable decimal.
4. Override the variable octal with quotient.
5. Repeat the steps 3 and 4 with the quotient obtained until the quotient becomes zero.
6. Print the variable decimal as output.

Runtime Test Cases
```Output:

Enter any octal number: 67
Equivalent decimal value: 55```

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