Answer:
#include <stdio.h>
int hexToDec(const int hexNum[]){
int result = 0, prod = 1;
for(int i = 3;i>=0;i-=1){
result += (prod*hexNum[i]);
prod = prod * 16;
}
return result;
}
int main()
{
int hexNum[4], i;
char s[5], ch;
printf("Enter hexa decimal value: ");
scanf("%s",s);
for(i = 0;i<4;i++){
ch = s[i];
if(ch>='0' && ch<='9'){
hexNum[i] = ch-'0';
}
else if((ch>='a' && ch<='f') || (ch>='A' && ch<='F')){
if(ch=='A' || ch=='a'){
hexNum[i] = 10;
}
else if(ch=='B' || ch=='b'){
hexNum[i] = 11;
}
else if(ch=='C' || ch=='c'){
hexNum[i] = 12;
}
else if(ch=='D' || ch=='d'){
hexNum[i] = 13;
}
else if(ch=='E' || ch=='e'){
hexNum[i] = 14;
}
else{
hexNum[i] = 15;
}
}
}
printf("%d",hexToDec(hexNum));
return 0;
}
Explanation:
