Hexadecimal to Decimal Conversion in C

 

// HEXADECIMAL to DECIMAL

#include <stdio.h>

#include <math.h> 

#include <string.h> 

int main()

{

int n=0,POWER=0,i,j;

char ar1[20];

char ar2[16] = {'0','1','2','3','4','5','6','7','8',

'9', 'A', 'B', 'C', 'D', 'E', 'F' }; 

printf("Enter any Hexadecimal Number : ");

scanf("%s",&ar1);

//let ar1 = A2C

for(i=strlen(ar1)-1;i>=0;i--)

//i=2,1,0

{

for(j=0;j<16;j++)

{

if(ar1[i]==ar2[j])

{

n=n+j*pow(16,POWER);

}

}

POWER++;

/*

step 1:

ar1[2]=C=ar2[12],it means j=12

n = 0+12*pow(16,0) = 0+12 = 12

POWER=1

step 2:

ar1[1]=2=ar2[2],it means j=2

n = 12+2*pow(16,1) = 12+32 = 44

POWER=2

step 2:

ar1[0]=A=ar2[10],it means j=10

n = 44+10*pow(16,2) = 44+2560 = 2604

POWER=3

n = 2604

*/

}

printf("\nDecimal Number = %d",n);

}

**Author**

Sukhvir Singh

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